<!-- ============================================================= -->
<!--  MODULE:    Common (Shared) Elements Module                   -->
<!--  VERSION:   2.2                                               -->
<!--  DATE:      April 2006                                        -->
<!--                                                               -->
<!-- ============================================================= -->

<!-- ============================================================= -->
<!--                    PUBLIC DOCUMENT TYPE DEFINITION            -->
<!--                        TYPICAL INVOCATION                     -->
<!--
"-//NLM//DTD Archiving and Interchange DTD Suite Common (Shared) Elements Module v2.2 20060430//EN"
Delivered as file "common.ent"                                     -->
<!-- ============================================================= -->



<!-- ============================================================= -->
<!-- SYSTEM:     Archiving and Interchange DTD Suite               -->
<!--                                                               -->
<!-- PURPOSE:    Defines the common parameter entities, calls the  -->
<!--             shared modules (such as special characters and    -->
<!--             notations) and provides declarations for elements -->
<!--             that do not properly fit into one class, since    -->
<!--             they can be used at more than one structural level-->
<!--                                                               -->
<!-- CONTAINS:   1) Default classes for elements defined in this   -->
<!--                module.  May be overridden by values in the    -->
<!--                DTD's Customization Module                     -->
<!--             2) Parameter Entities for attribute values        -->
<!--             3) Parameter Entities for content models          -->
<!--             4) Parameter Entities for attribute lists         -->
<!--             5) Elements used in many modules/classes          -->
<!--                  - Address elements                           -->
<!--                  - Date elements                              -->
<!--                  - Personal name elements                     -->
<!--                  - Common metadata elements (shared by both   -->
<!--                      article metadata and bibliographic       -->
<!--                      reference metadata                       -->
<!--                                                               -->
<!-- MODULES REQUIRED:                                             -->
<!--             1) Standard XML Special Characters Module         -->
<!--                                       (%xmlspecchars.ent;)    -->
<!--             2) Custom XML Special Characters (%chars.ent;)    -->
<!--             3) Notation Declarations    (%notat.ent;)         -->
<!--                                                               -->
<!-- CREATED FOR:                                                  -->
<!--             Digital archives and publishers who wish to       -->
<!--             create a custom XML DTD for original markup of    -->
<!--             journal literature, books, and related material,  -->
<!--             or for archiving and transferring such material   -->
<!--             between archives.                                 -->
<!--                                                               -->
<!--             This DTD is in the public domain. An organization -->
<!--             that wishes to create its own DTD from the suite  -->
<!--             may do so without permission from NLM.            -->
<!--                                                               -->
<!--             The suite has been set up to be extended using a  -->
<!--             new DTD file and a new DTD-specific customization -->
<!--             module to redefine the many Parameter Entities.   -->
<!--             Do not modify the suite directly or redistribute  -->
<!--             modified versions of the suite.                   -->
<!--                                                               -->
<!--             In the interest of maintaining consistency and    -->
<!--             clarity for potential users, NLM requests:        -->
<!--                                                               -->
<!--             1. If you create a DTD from the Archiving and     -->
<!--                Interchange DTD Suite and intend to stay       -->
<!--                compatible with the suite, then please include -->
<!--                the following statement as a comment in all of -->
<!--                your DTD modules:                              -->
<!--                   "Created from, and fully compatible with,   -->
<!--                    the Archiving and Interchange DTD Suite."  -->
<!--                                                               -->
<!--             2. If you alter one or more modules of the suite, -->
<!--                then please rename your version and all its    -->
<!--                modules to avoid any confusion with the        -->
<!--                original suite. Also, please include the       -->
<!--                following statement as a comment in all your   -->
<!--                DTD modules:                                   -->
<!--                   "Based in part on, but not fully compatible -->
<!--                    with, the Archiving and Interchange DTD    --> 
<!--                    Suite."                                    -->
<!--                                                               -->
<!--             Suggestions for refinements and enhancements to   -->
<!--             the DTD suite should be sent in email to:         -->
<!--                 archive-dtd@ncbi.nlm.nih.gov                  -->
<!--                                                               -->
<!-- ORIGINAL CREATION DATE:                                       -->
<!--             December 2002                                     -->
<!--                                                               -->
<!-- CREATED BY: Jeff Beck       (NCBI)                            -->
<!--             Deborah Lapeyre (Mulberry Technologies, Inc.)     -->
<!--             Bruce Rosenblum (Inera Inc.)                      -->
<!--                                                               -->
<!--             NLM thanks the Harvard University Libraries, both -->
<!--             for proposing that a draft archiving NLM DTD for  --> 
<!--             life sciences journals be extended to accommodate -->
<!--             journals in all disciplines and for sponsoring    -->
<!--             Bruce Rosenblum's collaboration with other DTD    -->
<!--             authors in completing Version 1.0. The Andrew W.  --> 
<!--             Mellon Foundation provided support for these      --> 
<!--             important contributions.                          -->
<!--                                                               -->
<!-- ============================================================= -->


<!-- ============================================================= -->
<!--                    DTD VERSION/CHANGE HISTORY                 -->
<!-- ============================================================= -->
<!--

     =============================================================

Version  Reason/Occasion                   (who) vx.x (yyyy-mm-dd)

     =============================================================
     Version 2.2                       (DAL/BTU) v2.2 (2006-04-30)
     
     Backwards-compatible changes to meet operational needs.
     Typical changes include adding attribute values and making 
     required elements optional.
     
 33. RELATED ARTICLE TYPE - Added new suggested value for 
     "partial-retraction"
     
 32. PRICE - Added new elements <price> and made a new class for it
     (-%price.class;) so that it can be added to <product>
     
 31. SIG-BLOCK - Added new elements <sig-block> and <sig>. A 
     <sig-block> may be located at the end of the <body> in journal 
     articles (Blue and Green) and at the end of sections <sec> in 
     books. It main contain one or more Signatures <sig> or just
     #PCDATA.
     
 30. LONG DESC - Added asterisk to the model for <long-desc>       
          
 29. SECTION MODELS
 
     a. Added new element <sec-meta> to the start of the content
        models for section (-%sec-model;) and section optional
        title model (-%sec-opt-title-model;). There are sections that
        are authored independently, even in journal articles, and 
        this is the start of allowing additional metadata for such
        sections. The first content for <sec-meta> will be 
        <contrib-group>
     
     b. New Parameter Entity -%sec-meta-model; to hold the
        content of the new element.
        
     c. New element declaration for <sec-meta>
     
 28. Updated public identifier to "v2.2 20060430//EN"          

     =============================================================
     Version 2.1                       (DAL/BTU) v2.1 (2005-06-30)
          
     Changed to MathML 2.0 and MathML 2.0 Character Sets
     Added new material requested by NCBI   
          
 27. JOURNAL-ID-ATTS - Removed the duplicate declaration
          
 26. RELATED-ARTICLE-ATTS - Changed to use the journal-id-atts
     Parameter Entity, which was moved to allow this use
          
 25. PUB-ID-TYPES - Added new values "doaj" and "manuscript"
     to pub-id-types and suggested journal ID types
          
 24. PERMISSIONS - Added a new <permissions> wrapper element to
     consolidate copyright and licensing information. For backwards
     compatibility, the new element will be added alongside the
     existing copyright elements. Best practice will be to use the
     new container, but <copyright-statement>, <copyright-year>,
     and <license> will be accepted in their old positions inside
     <article-meta>
      - Added <permissions> to the following models:
         - article-meta>
      - Added <copyright-holder> to <permissions>
      - Moved <copyright-year> here from article-meta module
      - Moved <license> here from article-meta module
      - Moved -%license-atts; here from article-meta module
      - Moved -%license-model; here from article-meta module
          
 23. DATE ATTS PARAMETER ENTITY - The Parameter Entity -%date-atts;
     was defined, but not used on the <date> element. Since the
     attribute list was hard-coded at the element, it could not
     be over-ridden. PE is now used.
          
 22. X-GENERATED TEXT - Added "xml:space" attribute with a value of
     "preserve" to the <x> element
          
 21. JOURNAL TITLES
       a) Defined new element <journal-subtitle>; used in
          <journal-meta>
          
 20. Updated public identifier to "v2.1 20050630" 

     =============================================================
     Version 2.0                       (DAL/BTU) v2.0 (2004-08-30)
     
     
     Major requirement changes led to the new release, producing
     DTD version "2.0":
       a) The splitting of the Archival and Interchange Tag Set 
          DTDs into three DTDs from two: an authoring DTD, an
          archive regularization and interchange DTD (the
          current Blue Publishing DTD), and a preservationist 
          archive DTD (the current Green Archiving and Interchange 
          DTD).
       b) AIT Working Group suggestions from the June 04 meeting 
          and June/July 2004 followup discussions
       c) Suite remodularization to meet new (and newly articulated)
          modularization requirements
       d) New or renamed classes and mixes to make modifications
          easier and more consistent

     
 29. NEW ELEMENT <x> GENERATED TEXT AND PUNCTUATION
     Added a container element to hold punctuation or other 
     generated text, typically when 1) an archive decides not 
     to have any text generated and thus to pre-generate such 
     things as commas or semicolons between keywords or 2) 
     when an archive receives text with <x> tags embedded and 
     wishes to retain them.

 28. PUBLISHER - Moved element here from %journalmeta.ent;
     module since Book DTD also needed it and was not including
     that module.

 27. PAGE ELEMENT ATTRIBUTES
     a. Made an Parameter Entity for:
        - %fpage-atts;
        - %elocation-id-atts;
     b. Gave %elocation-id-atts" the attribute "seq"
        
 26. PUB ID TYPES - Added the new attribute values to the
     Parameter Entity %pub-id-types;, which is used on <article>
     and other elements. New values: pmcid and art-access-id

 25. CUSTOM METADATA - Added the new <custom-meta> element, its
     components, and its wrapper. This element is used to insert
     name/value pairs for metadata elements that are in source
     material but were never envisioned by this DTD. Allowed this
     element at the end of <article-meta>.

 24. DATES 
     a. Made a new Parameter Entity %string-date-elements; to
        hold all the elements that may be mixed with #PCDATA
        inside a <string-date>
     b. Also used %date-parts.class; and %x.class; (currently
        used only in Green-Archiving) in the new PE 
        %string-date-elements;

 23. COMPLETE MODELS WHEN OVER-RIDING A MODEL 
     (for all Parameter Entities suffixed "-model")
     ### Customization Alert ###
     Made all the model over-rides consistent. Some included
     the outer parentheses, some did not. They all do now,
     as this is the most flexible system, allowing for
     #PCDATA, mixed, or element content. (This is in direct
     contrast to the "-element" suffixed models, which are
     designed to prohibit element content and permit only
     #PCDATA or mixed content.) Added parentheses to Parameter
     Entity and removed them from the Element Declaration.
     - %custom-meta-model;
     - %custom-meta-wrap-model;
     - %def-model;
     - %sec-model;
     - %sec-opt-title-model;
     - Removed parentheses from <notes>, <ack>, <address>, <date>

 22. CITATION MODEL / COPYRIGHT STATEMENT MODEL
     ### Customization Alert ###
     a. Replaced the Parameter Entity %copyright-statement-model; 
        with the OR list Parameter Entity 
        %copyright-statement-elements; and used that
        within the content model of <copyright-statement>
     b. Citation - In the PE %citation-elements; also
        changed the PE -%ext-links.class; ==> -%address-links.class;
        (Changed the content model of citation to match.)
     c. In -%copyright-statement-elements;, replaced the mix 
        -%rendition-plus; with its  constituent classes
     d. In -%citation-elements;, replaced the mix -%simple-text;
        with its constituent classes (with exception of 
        %address-link.class;).

 21. RELATED ARTICLE
     ### Customization Alert ###
      - Renamed 
         -%related-article-model; ==> -%related-article-elements;
          (To match the DTD naming convention that full content 
          models are named with a "-model" suffix and groups of 
          elements to be added to #PCDATA for a particular
          content model are named "-elements".)
      - Started "-related-article-elements" PE with an OR Bar
      - Deleted "ext-links.class", because these elements are 
        already in the %references.class; (no model change)

 20. INLINE MATH - <inline-formula> added to:
     - %label-elements; 

 19. RELATED ARTICLE ATTRIBUTES - Added the following attributes
     to the element <related-article>:
     a.  "id" - to provide a unique identifier
     b.  "alternate-form-of", which works (similarly to the same 
         attribute when used on a <graphic> element) to point to 
         another <related-article> element within the same document 
         as an alternate form of the related article.

 18. ISSUE TITLE <issue-title> - Created new element for a theme or
     special issue title
        - Defined here in the common module
        - Added to <article-meta>
        - Added to %references.class; (therefore to <citation>,
          <product>, and <related-article>
        - Created new Parameter Entities %issue-title-elements; 
          which hold the OR-group of elements that may be mixed with 
          #PCDATA inside the content model 

 17. ATTRIBUTION
      - Moved <attrib> and its Parameter Entities from the paragraph
        module to here, as it is numerous elements, such as <array>, 
        <boxed-text>, <fig>, <table-wrap>, etc., in the Archival DTD.

 16. CUSTOM METADATA - Added the new <custom-meta> element, its
     components, and its wrapper. This element is used to insert
     name/value pairs for metadata elements that are in source
     material but were never envisioned by this DTD. Allowed this
     element at the end of <article-meta> and <journal-meta>.

 15. EMAIL- Considered to be just another type of external link, as
     <ext-link> is, so added to:
     - %collab-elements;
     - %copyright-statement-elements;

 14. DATES 
     a. Added new class %date-parts.class; to hold all the
        potential components of date, such as <year>, <day>,
        etc.
     b. Made a new Parameter Entity %string-date-elements; to
        hold all the elements that may be mixed with #PCDATA
        inside a <string-date>
     c. Used %date-parts.class; in that model.

 13. ROLE ELEMENT - Was added to the model for <citation>, thus
     moved to this module from the article metadata module.


 12. NEW IDENTIFICATION ELEMENTS - in view of the larger role that 
     some publishers are giving to DOIs:

     a. OBJECT ID  -  Added a new class Parameter Entity 
        %id.class; to hold the new element <object-id> Object 
        Identifier. The <object-id> element is used to capture any 
        publisher's or archive's ID, such as a DOI. This was modeled 
        as an element (rather than as an attribute) to allow for 
        multiple  IDs. New PE used in:
          - %references.class (therefore inside <citation>, 
             <related-article>, and <product>)
          - metadata objects such as <abstract>
          - display objects such as <figure>.
        Added PE %object-id-atts; to hold the element's attributes
        
     b. ISSUE ID <issue-id> - new element for an identifier such 
        as a DOI associated with a journal issue (as opposed to the 
        existing element <issue>, which is defined as the issue 
        number) 
        - Defined here in the common module
        - Added to <article-meta>
        - Added to %references.class; (therefore to <citation>,
          <product>, and <related-article>
        - Created PE %issue-id-atts; to hold the attributes.

     c. VOLUME ID <volume-id> - new element for an identifier such 
        as a DOI associated with a volume of a journal (as opposed 
        to the  existing element <volume>, which is defined as the 
        volume number) 
        - Defined here in the common module
        - Added to <article-meta>
        - Added to %references.class; (therefore to <citation>,
          <product>, and <related-article>
        - Created new Parameter Entities %volume-id-elements; 
          which hold the OR-group of elements that may be mixed with 
          #PCDATA inside the content model 
        - Added PE %volume-id-atts; to hold the attributes.

     
     Note: All ID attributes for these new identification
     elements was set to use the "pub-id-type" attribute, 
     which is for Archival (Green) set as a CDATA attribute.

 11. NAME CLASS / STRING NAME / PERSON NAME CLASS
     a. Created a new element <string-name> for names that
        do not follow the former, strict personal name model.
        <string-name> holds any combination of #PCDATA and any of 
        the known personal-name elements such as <surname>.
        - Used a new Parameter Entity %string-name-elements;
          in the content model
     
     b. Created a new class %name.class; to hold all the ways
        to name people: <name>, <string-name>, and <collab>
        who produce products or articles.

     c. Allowed <string-name> to be used anywhere <name> is
        used. Inside
         - citation (by adding to %references.class;)
         - product  (by adding to %references.class;)

     d. Added new attribute "initials" to the personal name
        components: <surname> and <given-names>. This provides
        a way to preserve the initials, for matching services
        that prefer initials to full names. Since there are
        many cases in which the initials cannot be determined
        programmatically, we merely provide a bucket to record
        them.
        
     e. Added new Parameter Entities %given-name-atts; and
        %surname-atts; to hold the new "initials" attribute.

 10. ATTRIBUTE VALUE LISTS - The Green (Archival) DTD needed to
     change all explicit attribute value lists in the DTD to CDATA. 
     In the future, explicit list types will be a feature of the
     Blue (Publishing) and new Authoring DTDs. Therefore, added
     Parameter Entities to hold the following attributes:
       - date-type

  9. RELATED ARTICLE ATTRIBUTES - Added the following attributes
     to the element <related-article>:
      - "id ID #IMPLIED" attribute, so the related-article
        can be referenced.
      - "ext-link-type" - to indicate the type of link used to 
        point to the related article. Attribute was used with 
        exactly the same content (CDATA) and suggested values 
        as when used with the element <ext-link>.
      - "issue" - used (along with "vol", "page", and "journal-id")
         to provide metadata concerning the related article
      - "journal-id"- used (along with "vol", "page", and "issue")
         to provide metadata concerning the related article.
      - "journal-id-type" - Performs the same function that this
        attribute performs for the element <journal-id>. The
        "journal-id"  values are the same as those for existing 
        journal identifiers plus "issn".
      - "alternate-form-of", which works (similarly to the same 
        attribute when used on a <graphic> element) to point to 
        another <related-article> element within the same document 
        as an alternate form of the related article.
     
  8. PARAMETER ENTITY CLEANUP AND REGULARIZATION

     a. RENAME ELEMENT MIXES NOT TO END IN "-elements", since that
        suffix is reserved for mixes that are added to #PCDATA in
        a particular element
        ### Customization Alert ###
        Names ending in "-elements" saved for element-specific mixes
        that will be added to #PCDATA for one element
        -  %sec-back-matter-elements; ==> %sec-back-matter-mix;
               (Used in -%sec-model; and -%sec-opt-title-model;)
     
     b. NEW CLASSES - Largely for classing and modification reasons,
        the following new classes were added:
        - %date.class;
        - %def.class;
        - %degree.class;
        - %id.class; 
        - Removed duplicate %person-name.class;

     c. NEW MIXES - To correct potential classing problems, new 
        Parameter Entities were created. The following content 
        models were changed to use these new entities.
        - <etal>           -%etal-elements;
        - <ext-link>       -%ext-link-elements;
        - <fax>            -%fax-elements;
        - <given-names>    -%given-names-elements;
        - <issn>           -%issn-elements;
        - <issue>          -%issue-elements;
        - <label>          -%label-elements;
        - <long-desc>      -%long-desc-elements;
        - <phone>          -%phone-elements;
        - <prefix>         -%prefix-elements;
        - <publisher-name> -%publisher-name-elements;
        - <role>           -%role-elements;
        - <suffix>         -%suffix-elements;
        - <surname>        -%surname-elements;
        - <uri>            -%uri-elements;
        - <volume>         -%volume-elements;
        - <volume-id>      -%volume-id-elements;

        - <bio>      %bio-model; (which uses %just-para.class;)
        - <def>      %def-model;
        - <def>      %just-para.class;
 
     d. RENAME CLASSES
        ### Customization Alert ###
        Not all classes ended in the ".class" suffix. Changed the 
        following to add the class suffix:
        - %address-elements; (renamed -%address.class;) used in 
            - %aff-elements; 
            - %publisher-loc-elements;
            - %address-model;
        - %inline-math.class; used in -%label-elements; 
 
     e. PE %attrib-elements;
        ### Customization Alert ###
        Uses %emphasized-text; which now starts with an OR bar, so
        removed the OR bar from this PE.

     f. LINK CLASSES
        - In %aff-elements;, replaced %link.class; with
          the following classes (via use of %all-phrase;)
          (no DTD change):
            - %address-link.class;  (external used in addresses)
            - %simple-link.class;   (the internal links, same)
            - %article-link.class;  (for journal articles)
       -  In -%collab-elements;
            - Replaced -%ext-links.class; with the following class
              (via use of %all-phrase;)
              (no DTD change):
              - address-link.class; (external used in addresses)
            - Deleted -%inpara-address; 
              (No model change, %address-link.class; covers it.)
       -  In %copyright-statement-elements;, replaced 
          -%inpara-address; with -%address-link.class;
          (via use of %all-phrase;)

  7. DEFAULT CLASSES - Were moved from this module to 
     %default-classes.ent;

  6. Updated public identifier to "v2.0 20040830" 
     
     =============================================================
     Version 1.1                           (TRG) v1.1 (2003-11-01)

  5. Made <copyright-statement> model into a parameter entity in 
     order to add <ext-link> to the content model.
     Rationale:  Permit linkage between copyright statement and 
     copyright holder's site.

  4. Added attribute "content-type" to element <ack>. 
     Rationale: To identify and preserve the semantic intent of 
     semantically rich source documents.
               
  3. Added ID attribute to the following elements:
       - <ack> 
       - <address> 
       - <alt-text>
       - <ext-link> (by modifying %ext-link-atts;)
       - <institution>
       - <long-desc> 
       - <notes> (by modifying parameter entity %notes-atts;)
     Rationale: Provide unique identifier so these elements can be 
     linked to.  
     
  2. Added element <label> to content model of <aff> (by adding
     -%label.class; to parameter -%aff-elements;)
     Rationale: To provide <label>  when needed for format 
     over-ride.
     
     =============================================================
     Version 1.0 Changes Before Public Release
                                       (Lapeyre) v1.0 (2002-12-25)

  1. ETAL - Changed the content model of <etal> to replace the
     entire content model with a Parameter Entity, not just name 
     some elements that may mix with #PCDATA. Rationale: The 
     Authoring DTD would like to make <etal> EMPTY.         
                                                                   -->


<!-- ============================================================= -->
<!--                    PARAMETER ENTITY DEPENDENCIES             
                        Requires the following parameter entities
                        be defined before calling this module, 
                        usually accomplished in the Customization
                        Module for the specific DTD:
                        - %address.class;
                        - %break.class;
                        - %emphasis.class;
                        - %inline-display.class;
                        - %just-rendition;
                        - %label.class;
                        - %para-level;
                        - %references.class;
                        - %rendition-plus;
                        - %sec-back-matter-mix;
                        - %sec-level;
                        - %sec-opt-title-model;
                        - %simple-link.class;
                        - %simple-phrase;
                        - %simple-text;
                        - %subsup.class;
                        - %might-link-atts;                        -->
<!-- ============================================================= -->


<!-- ============================================================= -->
<!--                    PARAMETER ENTITIES FOR ATTRIBUTE VALUES    -->
<!-- ============================================================= -->


<!--                    HISTORY DATE TYPES                         -->
<!--                    The <history> element contains one or more 
                        <date> elements that record events in the 
                        life of a publication.          
          date-type     Attribute should only be used if the date
                        is one of the known types; otherwise omit
                        the attribute. 
                        Values are:
                          accepted    - Date manuscript was 
                                        accepted         
                          received    - Date manuscript received
                          rev-request - Date revisions were 
                                        requested or manuscript 
                                        was returned
                          rev-recd    - Date revised manuscript 
                                        was received               -->
<!ENTITY % date-types   "accepted | received | rev-request | 
                         rev-recd"                                   >


<!--                    ARTICLE/PUBLICATION IDENTIFIER TYPES       -->
<!--                    The "pub-id-type" attribute names the
                        type of identifier, or the organization or 
                        system that defined this identifier for the 
                        identifier of the journal article or a 
                        cited publication.
                           Used on the <article-id> element, which 
                        holds an identifier for the entire article.  
                           Also used on the <pub-id> element, which 
                        is an identifier for a publication cited in 
                        a bibliographic reference (citation).
                        Valid Types include:
                          art-access-id
                                 - Generic article accession id for
                                   interchange and retrieval between
                                   archives
                          coden  - Obsolete PDB/CCDC identifier (may
                                   be present on older articles)
                                   be present on older articles)
                          doaj   - Directory of Open Access Journals
                          doi    - Digital Object Identifier for
                                   the article
                          manuscript
                                   A manuscript
                          medline- NLM Medline identifier
                          other  - None of the named identifiers
                          pii    - Publisher Item Identifier, see
                                    /epub/piius.htm
                          pmcid  - PubMed Central identifier        
                          pmid   - PubMed ID (see
                                   www.ncbi.nlm.nih.gov/entrez/
                                   query.fcgi?db=PubMed)         
                          publisher-id - 
                                   Publisher's identifying number 
                                   such as an 'article-id', 'artnum',
                                   'identifier', 'article- number', 
                                   etc.
                          sici   - Serial Item and Contribution 
                                   Identifier (SICI). A journal 
                                   article may have more than one 
                                   SICI, one for a print version and
                                   one for an electronic version.  -->
<!ENTITY % pub-id-types  "art-access-id | coden | doaj | doi |
                          manuscript | medline | other | pii | 
                          pmcid |  pmid | publisher-id | sici"       >


<!-- ============================================================= -->
<!--                    PARAMETER ENTITIES FOR CONTENT MODELS      -->
<!-- ============================================================= -->


<!--                    DATE ELEMENTS MODEL                        -->
<!--                    The content models for elements that describe
                        dates, such as Publication Date <pub-date>
                        and History Dates <date>.  The <string-date>
                        element holds dates for which months and 
                        years are not given, for example "first 
                        quarter", "spring", etc.                   -->
<!ENTITY % date-model   "( ( (day?, month?) | season)?,
                          year?, string-date?)"                      >


<!--                    CONTENT MODEL FOR A STRUCTURAL SECTION     -->
<!--                    The model for a section that requires that a
                        section title be present, used for elements
                        such as Section and Appendix.              -->
<!ENTITY % sec-model    "(sec-meta?, label?, title, (%para-level;)*, 
                          (%sec-level;)*, 
                          (%sec-back-matter-mix;)* )"                >


<!--                    CONTENT MODEL FOR A SECTION METADATA       -->
<!--                    In some articles, each section has a different
                        author or some sections are authored by 
                        different contributors from the enclosing
                        article. This wrapper element for 
                        section-level metadata is used to capture
                        information concerning those contributors. -->
<!ENTITY % sec-meta-model
                        "(contrib-group*)"                           >


<!--                    CONTENT MODEL FOR AN UNTITLED SECTION      -->
<!--                    The model for a section-like structure that
                        may or may not have an initial title       -->
<!ENTITY % sec-opt-title-model
                        "(sec-meta?, label?, title?, (%para-level;)*,  
                          (%sec-level;)*, 
                          (%sec-back-matter-mix;)* )"                >


<!--                    LINK ELEMENTS                              -->
<!--                    Elements for use in the linking elements
                        such as <xref>, <target>, and <ext-link>   -->
<!ENTITY % link-elements 
                        "| %emphasis.class; | %subsup.class;"        > 


<!--                    TITLE ELEMENTS                             -->
<!--                    Elements for use in all the title elements
                        such as <title>, <subtitle>, <trans-title>,
                        etc.                       
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-phrase; is an 
                        inline mix, the OR bar is already there.   -->
<!ENTITY % title-elements   
                        "%simple-phrase; | %break.class;"            > 


<!-- ============================================================= -->
<!--                    PARAMETER ENTITIES FOR LINKING ATTRIBUTES  -->
<!-- ============================================================= -->
              

<!--                    XLINK LINK ATTRIBUTES                      -->
<!--                    Used for elements that are a link by
                        definition, such as the <xref> element.         
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename
             xlink:role Provides a URI reference pointing to some
                        resource that describes the role or function 
                        of this link           
             xlink:title
                        Describes the meaning of the link in a 
                        human-readable and displayable fashion
             xlink:show Describes the requested presentation when 
                        the link is traversed.  
                        Values are:
                          embed    Load the new presentation in the
                                   place of the link
                          new      Load a new window, frame, pane, or 
                                   other presentation
                          none     No clue for the application
                          other    Look to other markup for a clue
                          replace  Load the new resource in the same
                                   window, frame, pane, or other
                                   presentation context as the link
                                   started in
            xlink:actuate
                        When is the link traversed, and under whose
                        control.  
                        Values are:
                          none     No clue for the application
                          onLoad   Traverse the link immediately
                                   upon loading the link
                          onRequest
                                   User or software requests that the
                                   link be traversed
                          other    Look to other markup for a clue
                                                                   -->       
<!ENTITY % link-atts
            "xmlns:xlink CDATA                            #FIXED
                                     'http://www.w3.org/1999/xlink'
             xlink:type  (simple)                   #FIXED 'simple'
             xlink:href  CDATA                            #REQUIRED 
             xlink:role  CDATA                            #IMPLIED
             xlink:title CDATA                            #IMPLIED
             xlink:show  (embed | new | none | other | replace)
                                                          #IMPLIED
             xlink:actuate   
                         (none | onLoad | onRequest | other)          
                                                           #IMPLIED" >


<!--                    MIGHT LINK XLINK ATTRIBUTES                -->
<!--                    Used for elements which may need to link to
                        external sources or other objects within
                        the document, but may not necessarily act 
                        as a link at all.  The attribute
                        "xlink:href" identifies the object to which 
                        the link points.                           -->
<!ENTITY % might-link-atts
            "xmlns:xlink CDATA                             #FIXED
                                     'http://www.w3.org/1999/xlink'
             xlink:type  (simple)                   #FIXED 'simple'
             xlink:href  CDATA                             #IMPLIED 
             xlink:role  CDATA                             #IMPLIED
             xlink:title CDATA                             #IMPLIED
             xlink:show  (embed | new | none | other | replace)
                                                           #IMPLIED
             xlink:actuate   
                         (none | onLoad | onRequest | other)          
                                                           #IMPLIED" >


<!-- ============================================================= -->
<!--                    PARAMETER ENTITIES FOR ATTRIBUTES LISTS    -->
<!--                    (ALPHABETICAL ORDER)                       -->
<!-- ============================================================= -->
                                                                
                                                                 
<!--                    AFFILIATION ATTRIBUTES                     -->
<!--                    Attributes for the Affiliation <aff> 
                        element                                    -->
<!ENTITY % aff-atts
            "id         ID                                 #IMPLIED  
             rid        IDREFS                             #IMPLIED" >

                                                                
<!--                    BIOGRAPHY ATTRIBUTES                       -->
<!--                    Attributes for <bio> element    
             id         Unique identifier so the element may be
                        referenced 
             rid        Points to the identifier of an author or
                        authors                               
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename.               -->
<!ENTITY % bio-atts
             "id        ID                                #IMPLIED
              rid       IDREFS                            #IMPLIED
              %might-link-atts;"                                     >

                                                                
<!--                    COLLABORATION ATTRIBUTES                   -->
<!--                    Attributes for <collab>                    -->
<!--          collab-type
                        The type or role of the collaborators, 
                        what function did they play in the 
                        publication.
                        Suggested values include:
                          assignee 
                                  - Group or company to whom a patent 
                                    is awarded
                          authors - Content creators
                          editors - Content editors
                          compilers
                                  - Put together a composite work
                                    from multiple sources
                          guest-editors 
                                  - A group of editors that have been
                                    invited to edit all or part of a
                                    work
                          inventors 
                                  - Idea, software, or machine 
                                    creators
                          translators
                                  - Translated the cited work from 
                                    one language into another
             id         Unique identifier so that the collaboration
                        can be referenced
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ENTITY % collab-atts
            "collab-type       
                        CDATA                             #IMPLIED  
             id         ID                                #IMPLIED
             %might-link-atts;"                                      >


<!--                    EXTERNAL LINK ATTRIBUTES                   -->
<!--                    Attribute list for external links 
             ext-link-type 
                        Type of external link. Use this attribute
                        if the type of external link is one of the
                        ones below or another named type.
                        Suggested values include:
                            aoi         Astronomical Object Identifier 
                            doi         Digital Object Identifier
                            ec          Enzyme nomenclature - see
                              http://www.chem.qmw.ac.uk/iubmb/enzyme/
                            ftp         File transfer protocol
                            email       An email address
                            gen         GenBank identifier
                            genpept     Translated Protein-encoding
                                        sequence Database
                            highwire    HighWire press intrajournal 
                            pmid        PubMed identifier
                            pdb         Protein data bank. See 
                                        http://www.rcsb.org/pdb/
                            pgr         Plant gene register. See
                                        http://www.tarweed.com/pgr/
                            pir         Protein Information Resource
                                        see http://pir.georgetown.edu
                            pirdb       Protein Information Resource 
                                        see http://pir.georgetown.edu
                            pmc         PubMed Central identifier
                            sprot       Swiss-Prot. See
                                    http://www.ebi.ac.uk/swissprot/
                            uri         Website or web service    
             id         Unique identifier so the element may be
                        referenced 
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ENTITY %  ext-link-atts
             "ext-link-type 
                        CDATA                              #IMPLIED
              id        ID                                 #IMPLIED
              %might-link-atts;"                                     >

                                                                
<!--                    CITATION ATTRIBUTES                        -->
<!--                    Attributes for <citation>
             citation-type
                        Defines the type of work being referenced.
                        Suggested values include:
                          book         Book 
                          conf-proceedings
                                       Conference proceedings
                          discussion   Discussion among a group in
                                       some forum - public, private,
                                       or electronic, which may or
                                       may not be moderated
                          gov          Government publication
                          journal      Journal article
                          list         Listserv
                          other        None of the listed types
                          patent       Patent or patent application
                          personal-communication
                                       Informal or personal 
                                       communication, such as a 
                                       phone call or an email
                                       message
                          standard     Standards document issued by
                                       a recognized standards body,
                                       such as ISO, ANSI, IEEE, 
                                       OASIS, etc.
                          thesis       Work written as part of the
                                       completion of an advanced 
                                       degree
                          web          Website
             id         Unique identifier so the element may be
                        referenced 
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ENTITY % citation-atts
             "citation-type   
                        CDATA                              #IMPLIED  
              id        ID                                 #IMPLIED
              %might-link-atts;"                                     >


<!--                    DATE (HISTORICAL) ATTRIBUTES               -->
<!--         date-type  Attribute should only be used if the date
                        is one of the known types, otherwise omit
                        the attribute. Values are:
                          accepted    - Date manuscript was 
                                        accepted         
                          received    - Date manuscript received
                          rev-request - Date revisions were 
                                        requested or manuscript 
                                        was returned
                          rev-recd    - Date revised manuscript 
                                        was received               -->
<!ENTITY % date-atts
             "date-type (%date-types;)                     #IMPLIED" >


<!--                    GIVEN NAMES ATTRIBUTES                     -->
<!--         initials   The initial(s) for the given names of the
                        person. Particularly useful in those cases
                        that cannot be algorithmically determined. -->
<!ENTITY % given-names-atts
             "initials  CDATA                              #IMPLIED" >


<!--                    ISSN ATTRIBUTES                            -->
<!--                    Attribute list for <issn>                  -->
<!--                    Used to record the type of publication, for
                        example, a print-only publication versus
                        an electronic-only publication, in any of
                        several life stages.
                        Suggested values include:
                          epub        - Electronic publication
                          ppub        - Print publication
                          epub-ppub   - Published in both print and
                                        electronic form
                          epreprint   - Electronic preprint 
                                        dissemination    
                          ppreprint   - Print preprint dissemination     
                          ecorrected  - Corrected in electronic    
                          pcorrected  - Corrected in print     
                          eretracted  - Retracted in electronic    
                          pretracted  - Retracted in print         -->
<!ENTITY %  issn-atts
             "pub-type   CDATA                           #IMPLIED"   >
                                                                
                                                                 
<!--                    ISSUE IDENTIFIER ATTRIBUTES                -->
<!--                    Attributes for the <issue-id> element
             pub-id-type
                        Publication (article) Identifier Type
                        Names the type of identifier, or the 
                        organization or system that defined this 
                        identifier for the identifier of the journal 
                        article or a cited publication. This is an
                        optional CDATA attribute that should be used
                        whenever the type is known.
                           Used on the <article-id> element, which 
                        holds an identifier for the entire article.  
                           Also used on the <pubid> element, which 
                        is an identifier for a publication cited in 
                        a bibliographic reference (citation).
                        Suggested values include:
                          coden  - Obsolete PDB/CCDC identifier (may
                                   be present on older articles)
                          doaj   - Directory of Open Access Journals
                          doi    - Digital Object Identifier
                          manuscript
                                   A manuscript
                          medline- NLM Medline identifier
                          other  - None of the named identifiers
                          pii    - Publisher Item Identifier, see
                                    http://pubs.acs.org/epub/piius.htm
                                   or 
                                    http://www.aip.org/epub/piipr.html
                          pmid   - PubMed Central identifier (see
                                   www.ncbi.nlm.nih.gov/entrez/
                                   query.fcgi?db=PubMed)         
                          publisher-id 
                                 - Publisher's identifier such 
                                   as an 'article-id', 'artnum',
                                   'identifier', 'article- number', 
                                   'pub-id', etc.
                          sici   - Serial Item and Contribution 
                                   Identifier (SICI). A journal 
                                   article may have more than one 
                                   SICI, one for a print version and
                                   one for an electronic version.  -->
<!ENTITY % issue-id-atts
            "pub-id-type
                        CDATA                              #IMPLIED" >


<!--                    JOURNAL IDENTIFIER ATTRIBUTES              -->
<!--                    Attribute list for journal identifier 
                        <journal-id> element                       -->
<!--                    Indicates whose identifier this is, for
                        example, "pub-id" for a publisher's
                        identifier or "pmc" for PubMed Central.
                        Suggested values include:
                          archive Identifier assigned by an archive
                                  or other repository
                          aggregator
                                 Identifier assigned by a data
                                 aggregator
                          doaj   Directory of Open Access Journals
                          doi    Digital Object Identifier for the
                                 entire journal, not just for the
                                 article (rare)
                          index  Identifier assigned by an
                                 abstracting or indexing service
                          pmc    Identifier assigned by PubMed Central
                                 for example, the pmc journal 
                                 abbreviation such as "pnas", "mbc", 
                                 "nar", "molcellb", which may be the 
                                 same as the abbreviated journal 
                                 title
                          publisher-id 
                                 Identifier assigned by the content
                                 publisher, for example, "MOLEC", 
                                 "MOLCEL"
                          nlm-ta Identifier assigned by the 
                                 PubMed/Medline, and is typically
                                 the journal abbreviation, for 
                                 example, "Mol Biol Cell", "Nucleic
                                 Acids Res", which may be the
                                 same as the abbreviated journal 
                                 title.                            -->
<!ENTITY %  journal-id-atts
             "journal-id-type  
                        CDATA                            #IMPLIED  " > 
                                                                
                                                                 
<!--                    LICENSE ATTRIBUTES                         -->
<!--                    Attributes for the <license> element    
             license-type
                        The type of license granted on a journal
                        article, for example,"open-access" for a 
                        license permitting unrestricted use, 
                        distribution, and reproduction in any medium, 
                        provided the original  work is properly cited
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename.               -->
<!ENTITY % license-atts
            "license-type  
                        CDATA                              #IMPLIED
             %might-link-atts;"                                      >


<!--                    NOTES ATTRIBUTES                           -->
<!--                    Attribute list for <note>                  -->
<!--         notes-type To identify the type of note, if the type
                        can be/has been identified, for example,
                        "note-in-proof"                            
             id         Unique identifier so the element may be
                        referenced                                 -->
<!ENTITY % notes-atts
            "id         ID                                #IMPLIED
             notes-type CDATA                             #IMPLIED"  >
                                                                
                                                                 
<!--                    OBJECT IDENTIFIER ATTRIBUTES               -->
<!--                    Attributes for the <object-id> element
             pub-id-type
                        Publication (article) Identifier Type
                        Names the type of identifier, or the 
                        organization or system that defined this 
                        identifier for the identifier of the journal 
                        article or a cited publication. This is an
                        optional CDATA attribute that should be used
                        whenever the type is known.
                           Used on the <article-id> element, which 
                        holds an identifier for the entire article.  
                           Also used on the <pubid> element, which 
                        is an identifier for a publication cited in 
                        a bibliographic reference (citation).
                        Suggested values include:
                          coden  - Obsolete PDB/CCDC identifier (may
                                   be present on older articles)
                          doaj   - Directory of Open Access Journals
                          doi    - Digital Object Identifier
                          manuscript
                                   A manuscript
                          medline- NLM Medline identifier
                          other  - None of the named identifiers
                          pii    - Publisher Item Identifier, see
                                    http://pubs.acs.org/epub/piius.htm
                                   or 
                                    http://www.aip.org/epub/piipr.html
                          pmid   - PubMed Central identifier (see
                                   www.ncbi.nlm.nih.gov/entrez/
                                   query.fcgi?db=PubMed)         
                          publisher-id 
                                 - Publisher's identifier such 
                                   as an 'article-id', 'artnum',
                                   'identifier', 'article- number', 
                                   'pub-id', etc.
                          sici   - Serial Item and Contribution 
                                   Identifier (SICI). A journal 
                                   article may have more than one 
                                   SICI, one for a print version and
                                   one for an electronic version.  -->
<!ENTITY % object-id-atts
            "pub-id-type
                        CDATA                              #IMPLIED" >

                                                                
<!--                    RELATED ARTICLE ATTRIBUTES                 -->
<!--                    Attributes for <related-article>         
             id         Unique identifier so the element may be
                        referenced
             alt-form-of
                        Exactly like the "alt-form-of" attribute
                        used with <graphic>, this is an IDREF
                        attribute which points to the ID of another
                        <related-article> in the same document
                         rather than to an external file.
             related-article-type
                        Describes how the related article is
                        related to the current article. While any
                        value may be used, suggested values include:
                          addendum      Additional material for an
                                        article, generated too late
                                        to be added to the main text
                          commentary-article   
                                        Used in an commentary or
                                        editorial to link to the 
                                        article on which it is
                                        commenting
                          companion     Used in an article to link 
                                        to a companion (related
                                        or sibling) article 
                          corrected-article
                                        Used in a correction to link 
                                        to the article being 
                                        corrected. Sometimes called
                                        erratum.
                          in-this-issue Related article in the same
                                        journal issue
                          letter        A letter to the publication
                                        or a reply to such a
                                        letter
                          commentary    Used in an article to link 
                                        to its associated commentary
                                        or editorial 
                          correction-forward
                                        Used in an article to link
                                        forward to its associated 
                                        correction (rarely used)
                          partial-retraction  Partial retraction of 
                                      previously published material
                          retracted-article
                                        Used in a retraction to link 
                                        to the article being retracted
                          retraction-forward   
                                        Used in an article to link
                                        forward to its associated 
                                        retraction (rare)
             ext-link-type
                        Type of external link used to point to the
                        related article. Use this attribute
                        if the type of external link is one of the
                        ones below or another named type.
                        Suggested values include:
                            aoi         Astronomical Object Identifier 
                            doi         Digital Object Identifier
                            ec          Enzyme nomenclature - see
                              http://www.chem.qmw.ac.uk/iubmb/enzyme/
                            ftp         File transfer protocol
                            email       An email address
                            gen         GenBank identifier
                            genpept     Translated Protein-encoding
                                        sequence Database
                            highwire    HighWire press intrajournal 
                            pdb         Protein data bank. See 
                                        http://www.rcsb.org/pdb/
                            pgr         Plant gene register. See
                                        http://www.tarweed.com/pgr/
                            pir         Protein Information Resource
                                        see http://pir.georgetown.edu
                            pirdb       Protein Information Resource 
                                        see http://pir.georgetown.edu
                            pmc         PubMed Central identifier
                            pmid        PubMed identifier
                            sprot       Swiss-Prot. See
                                    http://www.ebi.ac.uk/swissprot/
                            uri         Website or web service    
             The next five attributes are used to identify the
             journal in which the related article was published. 
             vol        Volume of the journal in which the related
                        article exists.  It is best practice to
                        limit the scope to the current journal, 
                        the one in which the current article
                        resides.
             page       Page number of the related article. It is 
                        best practice to limit the scope to the 
                        current journal, the one in which the 
                        current article resides. The values for this 
                        attribute should be a first page or a page 
                        range.
             issue      Issue number of the related article. 
             journal-id Identifier for the journal which contains the
                        related article.
             journal-id-type   
                        Indicates whose identifier this is, for
                        example, "pub-id" for a publisher's
                        identifier or "pmc" for PubMed Central.
                        Suggested values include:
                          archive Identifier assigned by an archive
                                  or other repository
                          aggregator
                                 Identifier assigned by a data
                                 aggregator
                          doi    Digital Object Identifier for the
                                 entire journal, not just for the
                                 article (rare)
                          index  Identifier assigned by an
                                 abstracting or indexing service
                          issn   International Standard Serial Number
                                 of the journal in which the related
                                 article was published
                          pmc    Identifier assigned by PubMed 
                                 Central, for example, a pmc journal 
                                 abbreviation such as "pnas", "mbc", 
                                 "nar", "molcellb", which may be the 
                                 same as the abbreviated journal 
                                 title
                          publisher-id 
                                 Identifier assigned by the content
                                 publisher, for example, "MOLEC", 
                                 "MOLCEL"
                          nlm-ta Identifier assigned by the 
                                 PubMed/Medline, and is typically
                                 the journal abbreviation, for 
                                 example, "Mol Biol Cell", "Nucleic
                                 Acids Res", which may be the
                                 same as the abbreviated journal 
                                 title.
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename.               -->
<!ENTITY % related-article-atts
             "id        ID                                #IMPLIED
              alternate-form-of
                        IDREF                             #IMPLIED
              related-article-type
                        CDATA                             #REQUIRED
              ext-link-type 
                        CDATA                             #IMPLIED
              vol       CDATA                             #IMPLIED
              page      CDATA                             #IMPLIED  
              issue     CDATA                             #IMPLIED
              journal-id
                        CDATA                             #IMPLIED  
              %journal-id-atts;
              %might-link-atts;"                                     >


<!--                    SURNAME ATTRIBUTES                         -->
<!--         initials   The initial(s) for the given names of the
                        person. Particularly useful in those cases
                        that cannot be algorithmically determined. -->
<!ENTITY % surname-atts
             "initials  CDATA                              #IMPLIED" >
                                                                
                                                                 
<!--                    VOLUME IDENTIFIER ATTRIBUTES               -->
<!--                    Attributes for the <issue-id> element
             pub-id-type
                        Publication (article) Identifier Type
                        Names the type of identifier, or the 
                        organization or system that defined this 
                        identifier for the identifier of the journal 
                        article or a cited publication. This is an
                        optional CDATA attribute that should be used
                        whenever the type is known.
                           Used on the <article-id> element, which 
                        holds an identifier for the entire article.  
                           Also used on the <pubid> element, which 
                        is an identifier for a publication cited in 
                        a bibliographic reference (citation).
                        Suggested values include:
                          coden  - Obsolete PDB/CCDC identifier (may
                                   be present on older articles)
                          doaj   - Directory of Open Access Journals
                          doi    - Digital Object Identifier
                          manuscript
                                 - A manuscript
                          medline- NLM Medline identifier
                          other  - None of the named identifiers
                          pii    - Publisher Item Identifier, see
                                    http://pubs.acs.org/epub/piius.htm
                                   or 
                                    http://www.aip.org/epub/piipr.html
                          pmid   - PubMed Central identifier (see
                                   www.ncbi.nlm.nih.gov/entrez/
                                   query.fcgi?db=PubMed)         
                          publisher-id 
                                 - Publisher's identifier such 
                                   as an 'article-id', 'artnum',
                                   'identifier', 'article- number', 
                                   'pub-id', etc.
                          sici   - Serial Item and Contribution 
                                   Identifier (SICI). A journal 
                                   article may have more than one 
                                   SICI, one for a print version and
                                   one for an electronic version.  -->
<!ENTITY % volume-id-atts
            "pub-id-type
                        CDATA                              #IMPLIED" >


<!-- ============================================================= -->
<!--                    ELEMENT USED BY MORE THAN ONE CLASS        -->
<!-- ============================================================= -->


<!-- ============================================================= -->
<!--                    SIGNATURE BLOCK ELEMENTS                   -->
<!-- ============================================================= -->


<!--                    SIGNATURE BLOCK ELEMENTS                   -->
<!--                    Elements to be mixed with data characters
                        inside the content model for the 
                        <sig-block> element.                       -->
<!ENTITY % sig-block-elements 
                        "| %break.class; | %emphasis.class; |   
                         %inline-display.class; |
                         %just-base-display.class; | %sig.class; |
                         %subsup.class;"                             > 


<!--                    SIGNATURE BLOCK                            -->
<!--                    An area of text and graphic material placed
                        at the end of an article or section to hold
                        the graphical signature or other description
                        of the person responsible for or attesting
                        to the content. 
                        Best Practice: Although a <sig-block> is 
                        allowed to contain all the same complexity
                        as the Signature <sig>, to allow archives and
                        publishers to capture a published signature
                        block in any way it may have been constructed,
                        best practice is to act as if the Signature
                        Block contained the model (sig+) and build
                        as much of the complexity as possible into
                        the Signatures <sig>s.
                        Remarks: This element was deliberately left
                        out of the original NLM DTDs because analysis
                        seemed to indicate that signature blocks
                        merely duplicated information from the 
                        metadata and thus could be generated. However,
                        further samples, especially in published 
                        books, have indicated that signature blocks
                        are not as closely tied to contributor 
                        metadata as supposed and that a structure to
                        hold signatory material would be useful for
                        for previously published works.            -->
<!ELEMENT  sig-block    (#PCDATA %sig-block-elements;)*              >


<!--                    SIGNATURE ELEMENTS                         -->
<!--                    Elements to be mixed with data characters
                        inside the content model for the 
                        <sig> element.                             -->
<!ENTITY % sig-elements "%rendition-plus;| %break.class; | 
                         %inline-display.class; |
                         %just-base-display.class;"                  > 


<!--                    SIGNATURE                                  -->
<!--                    One contributor signature and associated 
                        material (such as a text restatement of the
                        affiliation) inside a signature block. 
                        Typically contains the graphical signature or 
                        other description of the person responsible 
                        for or attesting to the content.           -->
<!ELEMENT  sig          (#PCDATA %sig-elements;)*                    >


<!-- ============================================================= -->
<!--                    COMMON COPYRIGHT/PERMISSION ELEMENTS       -->
<!-- ============================================================= -->


<!--                    COPYRIGHT HOLDER ELEMENTS                  -->
<!--                    Elements to be mixed with data characters
                        inside the content model for the 
                        <copyright-holder> element. The elements 
                        subscript and superscript were included
                        because the dot com revolution produced some 
                        rather unusual business names.             -->
<!ENTITY % copyright-holder-elements 
                        "| %subsup.class;"                           > 


<!--                    COPYRIGHT HOLDER                           -->
<!--                    Name of the organizational or personal
                        entity that holds the copyright.
                        Remarks: There are three copyright elements,
                        1) The copyright statement, which is the
                        textual statement of the copyright, worded
                        in any way necessary, 2) the copyright
                        year, pulled out of the statement for 
                        use in metadata searching and aggregation,
                        and 3) the copyright holder, pulled out of
                        the statement for the same reasons.        -->
<!ELEMENT  copyright-holder
                        (#PCDATA %copyright-holder-elements;)*       >


<!--                    COPYRIGHT STATEMENT MODEL                  -->
<!--                    Content model for <copyright-statement>    -->
<!ENTITY % copyright-statement-elements 
                        "| %address-link.class;| %emphasis.class; | 
                         %subsup.class;"                             > 


<!--                    COPYRIGHT STATEMENT                        -->
<!--                    Copyright notice or statement, suitable for
                        printing or display. Within the statement the
                        copyright year should be identified, if
                        expected to be displayed.                  -->
<!ELEMENT  copyright-statement
                        (#PCDATA %copyright-statement-elements;)*    >


<!--                    COPYRIGHT YEAR                             -->
<!--                    Year of the copyright. Need not be used, if,
                        for example, having the year as part of the 
                        copyright statement is sufficient.
                        Note: since Copyright Statement is intended
                        for display, Copyright Year is not expected 
                        to be displayed (but will be available for 
                        searching).                                -->
<!ELEMENT  copyright-year    
                        (#PCDATA)                                    >


<!--                    LICENSE MODEL                              -->
<!--                    Content model for an <license> element     -->
<!ENTITY % license-model
                        "((%just-para.class;)+)"                     > 


<!--                    LICENSE INFORMATION                        -->
<!--                    The set of conditions under which people are
                        allowed to use this article or other
                        license-related information or restrictions.
                        For now, this is a place-holder element
                        that may change after the AIT Workgroup has
                        done additional analysis                   -->
<!ELEMENT  license      %license-model;                              >
<!ATTLIST  license  
             %license-atts;                                          >


<!--                    PERMISSIONS MODEL                          -->
<!--                    Model for <permissions> wrapper element    -->
<!ENTITY % permissions-model 
                        "(copyright-statement?, copyright-year?, 
                          copyright-holder?, license?)"              > 


<!--                    PERMISSIONS                                -->
<!--                    Wrapper element to hold the copyright
                        information, license material, and any 
                        future similar metadata.                   -->
<!ELEMENT  permissions
                        %permissions-model;                          >


<!-- ============================================================= -->
<!--                    COMMON METADATA/BIBLIOGRAPHIC ELEMENTS     -->
<!-- ============================================================= -->


<!--                    ARTICLE TITLE                              -->
<!--                    The title of the article in the language
                        in which the article was originally
                        published          
                        Remarks: The related element Translated Title
                        <trans-title> should be used for a
                        translation of the article into another
                        language, for example, to hold the English
                        version of a Japanese article title.       -->
<!ELEMENT  article-title       
                        (#PCDATA %title-elements;)*                  >
<!--         xml:lang   The language in which the value of the
                        element is expressed.  Recommended best 
                        practice is to use values as defined in
                        RFC 1766, typically 2-letter language
                        codes such as "FR" (French), "EN" (English),
                        and "DE" (German). These values are NOT
                        case sensitive, so "EN" = "en". The values
                        may include hyphenated differentiations such 
                        as "EN-AU" (Australian English) and "EN-US"
                        (United States English).                   -->
<!ATTLIST  article-title
             xml:lang   NMTOKEN                            #IMPLIED  > 


<!--                    AFFILIATION ELEMENTS                       -->
<!--                    Elements for use in the <aff> element      -->
<!ENTITY % aff-elements "| %address.class; | %address-link.class; |
                         %article-link.class; | %break.class; | 
                         %emphasis.class; | %label.class; | 
                         %simple-link.class; | %subsup.class;"       > 


<!--                    AFFILIATION                                -->
<!--                    Name of a institution or organization such as
                        a university or corporation. 
                        Authoring and Conversion Note: In a typical 
                        case, the "id" attribute will be pointed to 
                        by one or more contributors.               
                        Conversion Note: Any explicitly tagged numbers
                        or symbols for author linkages should be 
                        discarded, as the linkage will be recreated
                        from the "id" connection.
                        Authoring Note:  While this element 
                        contains an optional Label element, the 
                        Label element should be included only in 
                        those circumstances where a formatting 
                        override is needed; Label should NOT 
                        be used in the ordinary course of 
                        tagging.                                   -->                       
<!ELEMENT  aff          (#PCDATA %aff-elements;)*                    >
<!--         id         Unique identifier so that the affiliated
                        institution may be referenced, for example 
                        by a contributor
             rid        May be used to point to affiliation-related
                        information within the document            
                                                                   -->
<!ATTLIST  aff
             %aff-atts;                                              >


<!--                    COLLABORATIVE (GROUP) AUTHOR ELEMENTS      -->
<!--                    Elements for use in the <collab> element
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-text; is an inline
                        mix, the OR bar is already there. 
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-text; is an inline
                        mix, the OR bar is already there.          -->
<!ENTITY % collab-elements 
                        "%simple-text; | %address-link.class; | 
                         %simple-link.class;"                        > 


<!--                    COLLABORATIVE (GROUP) AUTHOR               -->
<!--                    Used for groups of authors credited under 
                        one name, either as a collaboration in the
                        strictest sense, or when an organization, 
                        institution, or corporation is the group.  
                        Remarks: When an author is an organization 
                        rather than a person, use the <collab> 
                        element rather than <surname>, for
                        example: 
                           <collab>Aardvark Institute</collab>  
                                                                   -->
<!ELEMENT  collab       (#PCDATA %collab-elements;)*                 >
<!--         collab-type
                        The type or role of the collaborators, 
                        what function did they play in the 
                        publication.
                        Suggested values include:
                          assignee 
                                  - Group or company to whom a patent 
                                    is awarded
                          authors - Content creators
                          editors - Content editors
                          compilers
                                  - Put together a composite work
                                    from multiple sources
                          guest-editors 
                                  - A group of editors that have been
                                    invited to edit all or part of a
                                    work
                          inventors 
                                  - Idea, software, or machine 
                                    creators
                          translators
                                  - Translated the cited work from 
                                    one language into another
                                    one language into another
             id         unique identifier so that the collaboration
                        can be referenced
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename.               -->
<!ATTLIST  collab
             %collab-atts;                                           >


<!--                    CONFERENCE DATE ELEMENTS                   -->
<!--                    Elements for use in the <conf-date> element-->
<!ENTITY % conf-date-elements 
                        "  "                                         > 
             

<!--                    CONFERENCE DATE                            -->
<!--                    The date(s) on which the conference was held.
                          Conference dates in journal headers are
                        traditionally stored in one of two forms:
                        as a single date ("May 1906") or as the
                        first day and last day of the conference.
                        Both types should be stored in this element;
                        the dates that come from separate first and 
                        last elements should be combined:
                          <conf-start>August 4, 2002</conf-start>
                          <conf-end>August 9, 2002<conf-end>
                        should become:
                          <conf-date>August 4, 2002 - August 9,
                          2002</conf-date>
                                                                   -->
<!ELEMENT  conf-date    (#PCDATA %conf-date-elements;)*              >


<!--                    CONFERENCE LOCATION ELEMENTS               -->
<!--                    Elements for use in the <conf-loc> element 
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-text; is an inline
                        mix, the OR bar is already there.          -->
<!ENTITY % conf-loc-elements 
                        "%simple-text;"                            > 
 

<!--                    CONFERENCE LOCATION                        -->
<!--                    The physical location(s) of the conference.
                        This may include a city, a country, or a
                        campus or organization location if that is
                        the only location available.
                        Authoring and Conversion Note: If the 
                        conference is in the United States, the 
                        state should also be provided. A specific 
                        venue or address (e.g. conference hotel) 
                        should not be provided unless there is no
                        other location information.                -->
<!ELEMENT  conf-loc     (#PCDATA %conf-loc-elements;)*               >


<!--                    CONFERENCE NAME ELEMENTS                   -->
<!--                    Elements for use in the <conf-name> element.
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-text; is an inline
                        mix, the OR bar is already there.          -->
<!ENTITY % conf-name-elements 
                        "%simple-text;"                            > 


<!--                    CONFERENCE NAME                            -->
<!--                    The full name of the conference, including any
                        qualifiers such as "43rd Annual". When the
                        name includes the year of the conference,
                        (e.g. "Extreme 2002"), the year should appear
                        in both the conference Name and the Conference
                        Date elements.                             -->
<!ELEMENT  conf-name    (#PCDATA %conf-name-elements;)*              >


<!--                    OBJECT IDENTIFIER                          -->
<!--                    Used to record an identifier such as a DOI
                        for an interior element such as an <abstract>
                        or <figure>.
                        Remarks: Such an identifier may be created
                        by a publisher or archive, and there is no
                        requirement that identifiers be unique.    -->
<!ELEMENT  object-id    (#PCDATA)                                    >  
<!--         pub-id-type
                        Indicates what type of identifier this is or
                        who assigned the identifier, for example,
                        "pub-id" for a publisher's non-DOI
                        identifier or "DOI" for a Digital Object
                        Identifier.
                          In Archival this is a CDATA attribute but
                        suggested values include:
                          archive Identifier assigned by an archive
                                  or other repository
                          aggregator
                                 Assigned by a data aggregator
                          doaj   Directory of Open Access Journals
                          doi    Digital Object Identifier
                          index  Assigned by an abstracting or 
                                 indexing service
                          pmc    Assigned by PubMed Central
                          publisher-id 
                                 Non-DOI Identifier assigned by 
                                 the content publisher             -->
<!ATTLIST  object-id
             %object-id-atts;                                        >


<!--                    ISSUE TITLE ELEMENTS                       -->
<!--                    Elements for use with data characters inside
                        the model for the <issue> element          -->
<!ENTITY % issn-elements 
                        " "                                          > 


<!--                    ISSN                                       -->
<!--                    International Standard Serial Number       -->
<!ELEMENT  issn         (#PCDATA %issn-elements;)                    >
<!--                    Used to record the type of publication, for
                        which this ISSN was issued, for example, 
                        a print-only publication versus
                        an electronic-only publication, in any of
                        several life stages.
                        Suggested values include:
                          epub        - Electronic publication
                          ppub        - Print publication
                          epub-ppub   - Published in both print and
                                        electronic form
                          epreprint   - Electronic preprint 
                                        dissemination    
                          ppreprint   - Print preprint dissemination     
                          ecorrected  - Corrected in electronic    
                          pcorrected  - Corrected in print     
                          eretracted  - Retracted in electronic    
                          pretracted  - Retracted in print     
                          -->
<!ATTLIST  issn
             %issn-atts;                                             >


<!--                    ISSUE TITLE ELEMENTS                       -->
<!--                    Elements for use with data characters inside
                        the model for the <issue> element          -->
<!ENTITY % issue-elements 
                        "%just-rendition;"                           > 


<!--                    ISSUE NUMBER                               -->
<!--                    NEW DEFINITION FOR RELEASE 2.0:
                        The issue number, issue name, or other 
                        identifier of an issue of a journal that
                        is displayed or printed with the issue. 
                        This is not the machine-readable internal 
                        identifier such as a DOI or SICI, that is
                        the related element <issue-id>             -->
<!ELEMENT  issue        (#PCDATA %issue-elements;)*                  >  


<!--                    ISSUE IDENTIFIER                           -->
<!--                    Used to record an identifier such as a DOI
                        that describes an entire issue of a 
                        journal                                    -->
<!ELEMENT  issue-id     (#PCDATA)                                    >  
<!--         pub-id-type    
                        Indicates what type of identifier this is or
                        who assigned the identifier, for example,
                        "pub-id" for a publisher's non-DOI
                        identifier or "DOI" for a Digital Object
                        Identifier.
                          In Archival this is a CDATA attribute but
                        suggested values include:
                          archive Identifier assigned by an archive
                                  or other repository
                          aggregator
                                 Assigned by a data aggregator
                          doaj   Directory of Open Access Journals
                          doi    Digital Object Identifier
                          index  Assigned by an abstracting or 
                                 indexing service
                          pmc    Assigned by PubMed Central
                          publisher-id 
                                 Non-DOI Identifier assigned by 
                                 the content publisher             -->
<!ATTLIST  issue-id
             %issue-id-atts;                                         >


<!--                    ISSUE TITLE ELEMENTS                       -->
<!--                    Elements for use in the <issue-title> element
                                                                   -->
<!ENTITY % issue-title-elements 
                        ""                                           > 


<!--                    ISSUE TITLE                                -->
<!--                    Used to record the theme or special issue
                        title for an issue of the journal          -->
<!ELEMENT  issue-title  (#PCDATA %issue-title-elements;)*            >  


<!--                    ROLE ELEMENTS                              -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <role>                    
                        Design Note: All inline mixes begin with an
                        OR bar; since %rendition-plus; is an 
                        inline mix, the OR bar is already there.   -->  
<!ENTITY % role-elements
                        "%rendition-plus;"                           >


<!--                    ROLE OR FUNCTION TITLE OF CONTRIBUTOR      -->
<!--                    A title or the role of a contributor
                        (such as an author) in this work. For example,
                        Editor-in-Chief, Contributor, Chief
                        Scientist, Photographer, Research Associate,
                        etc.              
                        Remarks: Information on the role or type of
                        contribution is collected in two places,
                        in the "contrib-type" attribute on the
                        Contributor element and in the Role element.  
                        For example, the Contributor attribute might 
                        have a value of "editor", while the content 
                        of the role element could be "Associate 
                        Editor". As another example, the contributor
                        attribute might be "author" and the role
                        element might be "Principle Author".
                        The <role> element is also more likely to 
                        appear on screen or in print than the 
                        contributor attribute value.               -->
<!ELEMENT  role         (#PCDATA %role-elements;)*                   >


<!--                    VOLUME NUMBER ELEMENTS                     -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <volume>                                 -->
<!ENTITY % volume-elements
                        "%just-rendition; "                          >


<!--                    VOLUME NUMBER                                     -->
<!--                    NEW DEFINITION FOR RELEASE 2.0:
                        The volume number, volume name, or other 
                        identifier of an volume of a journal that
                        is displayed or printed with the volume. 
                        This is not the machine-readable internal 
                        identifier such as a DOI or SICI, that is
                        the related element <volume-id>            -->
<!ELEMENT  volume       (#PCDATA %volume-elements;)*                 >


<!--                    TRANSLATED SUBTITLE                        -->
<!--                    An alternate version of an article subtitle 
                        that has been translated out of the original 
                        language of the article subtitle <subtitle>  
                        Remarks: The related element <subtitle>
                        should be used for the subtitle of the 
                        article in the original language in 
                        which it was published. This translated
                        subtitle is used for a translation of the 
                        original subtitle, for example an English 
                        version of a Japanese subtitle             -->
<!ELEMENT  trans-subtitle  
                        (#PCDATA %title-elements;)*                  >
<!--         xml:lang   The language in which the value of the
                        element is expressed.  Recommended best 
                        practice is to use values as defined in
                        RFC 1766, typically 2-letter language
                        codes such as "FR" (French), "EN" (English),
                        and "DE" (German).  These values are NOT
                        case sensitive, so "EN" = "en". The values
                        may include hyphenated differentiations such 
                        as "EN-AU" (Australian English) and "EN-US"
                        (United States English).
                          Authoring and Conversion Note: For the
                        Translated Title element, the xml:lang
                        attribute should always be set if the
                        value is known. The only reason the
                        attribute was not made #REQUIRED was that
                        there may be cases where the language is
                        not known.                                 -->
<!ATTLIST  trans-subtitle
             xml:lang   NMTOKEN                            #IMPLIED  >


<!--                    TRANSLATED TITLE                           -->
<!--                    An alternate version of the title that has
                        been translated into a language other than
                        that of the original article title 
                        <article-title>  
                        Remarks: The related element Article Title
                        <article-title> should be used for the title
                        of the article in the original language in 
                        which it was published. This element is used
                        for a translation of that title, for example
                        the English version of a Japanese article. -->
<!ELEMENT  trans-title  (#PCDATA %title-elements;)*                  >
<!--         xml:lang   The language in which the value of the
                        element is expressed.  Recommended best 
                        practice is to use values as defined in
                        RFC 1766, typically 2-letter language
                        codes such as "FR" (French), "EN" (English),
                        and "DE" (German).  These values are NOT
                        case sensitive, so "EN" = "en". The values
                        may include hyphenated differentiations such 
                        as "EN-AU" (Australian English) and "EN-US"
                        (United States English).
                          Authoring and Conversion Note: For the
                        Translated Title element, the xml:lang
                        attribute should always be set if the
                        value is known. The only reason the
                        attribute was not made #REQUIRED was that
                        there may be cases where the language is
                        not known.                                 -->
<!ATTLIST  trans-title
             xml:lang   NMTOKEN                            #IMPLIED  >


<!--                    VOLUME IDENTIFIER ELEMENTS                 -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <volume-id>                              -->
<!ENTITY % volume-id-elements
                        "%just-rendition; "                          >


<!--                    VOLUME IDENTIFIER                          -->
<!--                    Used to record an identifier such as a DOI
                        that describes an entire volume of a 
                        journal.
                           Remarks: The related elements <volume>
                        holds the volume number as published
                        with the journal.                          -->
<!ELEMENT  volume-id    (#PCDATA %volume-id-elements;)*              >
<!--         pub-id-type    
                        Indicates what type of identifier this is or
                        who assigned the identifier, for example,
                        "pub-id" for a publisher's non-DOI
                        identifier or "DOI" for a Digital Object
                        Identifier.
                          In Archival this is a CDATA attribute but
                        suggested values include:
                          archive Identifier assigned by an archive
                                  or other repository
                          aggregator
                                 Assigned by a data aggregator
                          doaj   Directory of Open Access Journals
                          doi    Digital Object Identifier
                          index  Assigned by an abstracting or 
                                 indexing service
                          pmc    Assigned by PubMed Central
                          publisher-id 
                                 Non-DOI Identifier assigned by 
                                 the content publisher             -->
<!ATTLIST  volume-id
             %volume-id-atts;                                        >


<!-- ============================================================= -->
<!--                    COMMON METADATA ELEMENTS CONTINUED         -->
<!--                    PUBLISHER IDENTIFICATION ELEMENTS          -->
<!--                    (COMMON ARTICLE METADATA/BIBLIOGRAPHIC)    -->
<!--                    Used in article metadata and also inside   -->
<!--                    a bibliographic reference (citation)       -->
<!-- ============================================================= -->


<!--                    ET AL ELEMENTS                             -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        an <etal>                                  -->
<!ENTITY % etal-elements
                        "%just-rendition; "                          >


<!--                    ET AL CONTENT MODEL                        -->
<!--                    The content model for the <etal> element   -->
<!ENTITY % etal-model   "(#PCDATA %etal-elements;)*"                 > 


<!--                    ET AL                                      -->
<!--                    Most journals model this as an EMPTY element,
                        typically used to generate the text "et al." 
                        from a stylesheet. However, a few journal
                        DTDs (Blackwell's, for example) expect
                        content for this element, with such text as
                        "Associates, coworkers, and colleagues".
                        Note: Therefore (as of Version 2.0, this is 
                        an EMPTY element in the more prescriptive DTD
                        Publishing, a #PCDATA element in Archiving,
                        and not used at all in the Authoring DTD.  -->
<!ELEMENT  etal         %etal-model;                                 >  


<!--                    PUBLISHER                                  -->
<!--                    Who published the work                     -->
<!ELEMENT  publisher    (publisher-name, publisher-loc?)             >


<!--                    PUBLISHER'S NAME ELEMENTS                  -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <publisher-name>
                        Design Note: All inline mixes begin with an
                        OR bar; since %just-rendition; is an 
                        inline mix, the OR bar is already there    -->  
<!ENTITY % publisher-name-elements
                        "%just-rendition; "                          >


<!--                    PUBLISHER'S NAME                           -->
<!--                    Name of the publisher of the work          -->
<!ELEMENT  publisher-name      
                        (#PCDATA %publisher-name-elements;)*         >  


<!--                    PUBLISHER'S LOCATION ELEMENTS              -->
<!--                    Elements for use in the Publisher Location
                        <publisher-loc> element                    -->
<!ENTITY % publisher-loc-elements 
                        "| %address.class; | %address-link.class; |
                         %emphasis.class; | %subsup.class;"          > 


<!--                    PUBLISHER'S LOCATION                       -->
<!--                    Place of publication, usually a city such
                        as New York or London                      -->
<!ELEMENT  publisher-loc       
                        (#PCDATA %publisher-loc-elements;)*          >


<!-- ============================================================= -->
<!--                    COMMON METADATA ELEMENTS CONTINUED         -->
<!--                    PAGE NUMBERING ELEMENTS                    -->
<!-- ============================================================= -->


<!--                    FIRST PAGE ATTRIBUTES                      -->
<!--         seq        Used for sequence number or letter for 
                        journals (such as continuous makeup journals) 
                        with more than one article starting on the 
                        same page                                  -->
<!ENTITY % fpage-atts
             "seq        CDATA                             #IMPLIED" >

<!--                    FIRST PAGE                                 -->
<!--                    The page number on which the article starts,
                        for print journals that have page numbers  -->
<!ELEMENT  fpage        (#PCDATA)                                    >
<!--         seq        Used for sequence number or letter for 
                        journals (such as continuous makeup journals) 
                        with more than one article starting on the 
                        same page                                  -->
<!ATTLIST  fpage
             %fpage-atts;                                            >
             

<!--                    LAST PAGE                                  -->
<!--                    The page number on which the article ends,
                        for print journals that have page numbers  -->
<!ELEMENT  lpage        (#PCDATA)                                    >
             

<!--                    PAGE RANGES                                -->
<!--                    A container element for additional page 
                        information (TO BE USED TO SUPPLEMENT AND
                        NOT TO REPLACE <fpage> and <lpage>) to record
                        discontinuous pages ranges such as 
                            "8-11, 14-19, 40"
                        meaning that the article begins on page
                        8, runs 8 through 11, skips to pages 14 
                        through 19, and concludes on page 40.      -->
<!ELEMENT  page-range   (#PCDATA)                                    >


<!--                    ELECTRONIC LOCATION IDENTIFIER ATTRIBUTES  -->
<!--         seq        Used for sequence number or letter for 
                        journals (such as continuous makeup journals) 
                        so that the publisher's sequence of articles
                        can be preserved, even for electronic
                        publications.                              -->
<!ENTITY % elocation-id-atts
             "seq        CDATA                             #IMPLIED" >


<!--                    ELECTRONIC LOCATION IDENTIFIER             -->
<!--                    Used to identify an article that 
                        does not have traditional page numbers. 
                        For a printed article, when citations are 
                        sent through the Medline matcher to be turned
                        into live links or when the metadata about an
                        article is collected for complete
                        identification,  the first page number (and 
                        sometimes  also the last page number) of the 
                        article is recorded to help indicate which
                        article is being referenced. Electronic only
                        journals have no page numbers, so this
                        element is used as the equivalent identifier,
                        the "electronic page number" that helps to
                        identify the article. The value could be an 
                        article identifier, a doi, etc., for 
                        example, "E70".                        
                        Remarks: This element is more accurately an
                        electronic identifier, and it was considered
                        renaming this element to that. The purpose
                        of the name is to be a parallel with the
                        <fpage>...<lpage> model. When neither first
                        page or last page is appropriate, because
                        the electronic journal has no pages, the
                        <elocation-id> element is used instead.    -->
<!ELEMENT  elocation-id (#PCDATA)                                    >
<!--         seq        Used for sequence number or letter for 
                        journals (such as continuous makeup journals) 
                        with more than one article starting on the 
                        same page                                  -->
<!ATTLIST  elocation-id 
             %elocation-id-atts;                                     >


<!-- ============================================================= -->
<!--                    CITATION (BIBLIOGRAPHIC REFERENCE)         -->
<!-- ============================================================= -->


<!--                    CITATION ELEMENTS                          -->
<!--                    Content model for the <citation> element. 
                        Design Note: All inline mixes begin with an
                        OR bar.                                    -->
<!ENTITY % citation-elements   
                        "| %emphasis.class; | %inline-display.class; |
                         %inline-math.class; | %label.class; | 
                         %phrase.class; | %references.class; |
                         %subsup.class;"                             > 


<!--                    CITATION                                   -->
<!--                    A citation is a description of a work, such
                        as a journal article, book, or personal
                        communication, that is cited in the text of
                        the article. Although the DTD does not
                        enforce it, a citation to a journal article
                        *should* be tagged with as many as possible 
                        of the following, so that PubMed Central or
                        other matching processing can make the 
                        citation into a live link:
                           source  The MEDLINE abbreviation of the
                                   journal name
                           article-title  
                                   Title of the article
                           volume  Volume of the journal
                           issue   Issue of the journal
                           fpage   Page number on which the article
                                   starts
                           name    Of an author or editor
                           year    Year of publication
                           month   Month of publication (if present)
                           day     Date of publication (if present)
                        The other elements may be tagged if
                        desired.  The <title> element may be used
                        for titles of books, conference proceedings,
                        etc.
                        Authoring and Conversion Note: In order to 
                        make citations into live links, as much
                        of the author and date information as is
                        available should be preserved. The most
                        important date tag is year, and it should
                        always be tagged if possible:
                            <year>2003</year> 
                        The <day> and <month> tags will be used
                        more rarely; they are provided because some
                        of the citation matching services can use
                        the month and the day if they are available.
                                                                   -->
<!ELEMENT  citation     (#PCDATA %citation-elements;)*               >
<!--         citation-type
                        Defines the type of work being referenced.
                        Suggested values include:
                          book         Book 
                          personal-communication
                                       Informal or personal 
                                       communication, such as a 
                                       phone call or an email
                                       message
                          conf-proceedings
                                       Conference proceedings
                          discussion   Discussion among a group in
                                       some forum - public, private,
                                       or electronic, which may or
                                       may not be moderated
                          gov          Government publication
                          journal      Journal article
                          list         Listserv
                          other        None of the listed types
                          patent       Patent or patent application
                          thesis       Work written as part of the
                                       completion of an advanced 
                                       degree
                          web          Website
             id         Unique identifier so the element may be
                        referenced 
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ATTLIST  citation
             %citation-atts;                                         >
             

<!-- ============================================================= -->
<!--                    ADDRESS ELEMENTS (BIBLIOGRAPHIC)           -->
<!-- ============================================================= -->


<!--                    ADDRESS MODEL                              -->
<!--                    Content model for the <address> element    -->
<!ENTITY % address-model    
                        "(%address.class; | %address-link.class;)*"  >


<!--                    ADDRESS/CONTACT INFORMATION                -->
<!--                    Wrapper element for contact information such 
                        as address, phone, fax, email, url, country,
                        etc.                                       -->
<!ELEMENT  address      %address-model;                              >
<!--         id         Unique identifier so the element may be
                        referenced                                 -->
<!ATTLIST  address
             id         ID                                 #IMPLIED  >


<!--                    ADDRESS LINE ELEMENTS                      -->
<!--                    Elements for use in the <addr-line> element-->
<!ENTITY % addr-line-elements 
                        "%simple-text;"                              > 


<!--                    ADDRESS LINE                               -->
<!--                    One line in an address                     -->
<!--                    Conversion Note: If the address is 
                        undifferentiated data characters, the entire
                        address may be inside one of these elements.
                                                                   -->
<!ELEMENT  addr-line    (#PCDATA %addr-line-elements;)*              >


<!--                    COUNTRY:  IN AN ADDRESS                    -->
<!ELEMENT  country      (#PCDATA)                                    >


<!--                    EMAIL ADDRESS ELEMENTS                     -->
<!--                    Elements to be mixed with #PCDATA inside the
                        <email> element                            -->
<!ENTITY % email-elements 
                        " "                                          > 


<!--                    EMAIL ADDRESS                              -->
<!ELEMENT  email        (#PCDATA %email-elements;)*                  >
<!--         xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ATTLIST  email
             %might-link-atts;                                       >


<!--                    FAX NUMBER ELEMENTS                        -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <fax>                                    -->
<!ENTITY % fax-elements
                        "%just-rendition; "                          >


<!--                    FAX NUMBER: IN AN ADDRESS                  -->
<!ELEMENT  fax          (#PCDATA %fax-elements;)*                    >


<!--                    INSTITUTION NAME ELEMENTS                  -->
<!--                    Elements for use in the <institution> 
                        element                                    -->
<!ENTITY % institution-elements 
                        "| %break.class; | %emphasis.class; |
                         %subsup.class;"                             > 


<!--                    INSTITUTION NAME: IN AN ADDRESS            -->
<!--                    Name of a institution or organization such as
                        a university or corporation                -->
                        
<!ELEMENT  institution  (#PCDATA %institution-elements;)*            >
<!--         id         Unique identifier so the element may be
                        referenced                                 
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ATTLIST  institution
             id         ID                                 #IMPLIED  
             %might-link-atts;                                       > 


<!--                    PHONE NUMBER ELEMENTS                      -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <phone number> 
                        Design Note: All inline mixes begin with an
                        OR bar, but since %just-rendition; is an 
                        inline mix, the OR bar is already there.   -->
<!ENTITY % phone-elements
                        "%just-rendition;"                           >


<!--                    PHONE NUMBER: IN AN ADDRESS                -->
<!--                    A callable phone number in some telephone or
                        wireless system somewhere in the world.
                        Typically includes area code; may include
                        country extension, especially for non-US.  -->
<!ELEMENT  phone        (#PCDATA %phone-elements;)*                  >


<!--                    URI ELEMENTS                               -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <uri>
                        Design Note: This PE begins with an OR
                        bar because %just-rendition; begins with an
                        OR bar.                                    -->
<!ENTITY % uri-elements
                        "%just-rendition;"                           >


<!--                    URI                                        -->
<!--                    URI such as a URL that may be used as a 
                        live link, typically naming a website, such 
                        as:
                           <url>http://www.mulberrytech.com</url>
                        Alternatively the element content may name
                        the URL, e.g., "Mulberry's Website" and the
                        "xlink:href" attribute may hold the real
                        URL.
                           <url xlink:href="http://www.mulberrytech.
                           com">Mulberry's Website</url>           
                        Related Elements: A URI used outside the 
                        context of an address of contributor should 
                        be tagged as an External Link <ext-link>   -->
<!ELEMENT  uri          (#PCDATA %uri-elements;)*                    >

<!ATTLIST  uri
             %might-link-atts;                                       >


<!-- ============================================================= -->
<!--                    DATE ELEMENTS (PUBLICATION HISTORY)        -->
<!-- ============================================================= -->


<!--                    DATE                                       -->
<!--                    The elements <day>, <month>, and <year> should 
                        ALWAYS be numeric values. The date may be 
                        represented as a string in <string-date>, but
                        the numeric values should be present whenever
                        possible.                                  -->
<!ELEMENT  date         %date-model;                                 >
<!--         date-type  Attribute should only be used if the date
                        is one of the known types, otherwise omit
                        the attribute. Values are:
                          accepted    - Date manuscript was 
                                        accepted         
                          received    - Date manuscript received
                          rev-request - Date revisions were 
                                        requested or manuscript 
                                        was returned
                          rev-recd    - Date revised manuscript 
                                        was received               -->
<!ATTLIST  date
              %date-atts;                                            >


<!--                    DAY                                        -->
<!--                    The numeric value of a day of the month, used
                        in both article metadata and inside a citation,
                        in two digits as it would be stated in the "DD" 
                        in an international date format YYYY-MM-DD, for
                        example "03", "25".                        -->
<!ELEMENT  day          (#PCDATA)                                    >


<!--                    MONTH                                      -->
<!--                    Names one of the months of the year. Used in
                        both article metadata and inside a citation,
                        this element may contain a full month 
                        "December", an abbreviation "Dec", or, 
                        preferably, a numeric month such as "12".
                        Authoring and Conversion Note: For ease in
                        comparisons and searching, many archives
                        prefer that months be converted to numeric
                        Suggested values:
                          1 = January
                          2 = February
                          3 = March, etc.                          -->
<!ELEMENT  month        (#PCDATA)                                    >


<!--                    SEASON                                     -->
<!--                    Season of publication, such as "Spring". 
                        Used in both article metadata and inside a 
                        citation                                   -->
<!ELEMENT  season       (#PCDATA)                                    >


<!--                    YEAR                                       -->
<!--                    Year of publication, which should be expressed
                        as a 4-digit number: "1776" or "1924"      -->
<!ELEMENT  year         (#PCDATA)                                    >


<!--                    STRING DATE ELEMENTS                       -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        the <string-date> element                  -->
<!ENTITY % string-date-elements 
                        " | %date-parts.class;"                      >


<!--                    DATE AS A STRING                           -->
<!--                    This is a representation of the date as a 
                        string. Usually used for dates for which 
                        months and years are not given, but may be
                        used for any date as a string (i.e., "January, 
                        2001" "Fall 2001" "March 11, 2001".
                        It is better practice to tag the year
                        and month as numbers with a date such
                        as "January, 2001" or "March 11, 2001".    -->
<!ELEMENT  string-date  (#PCDATA %string-date-elements;)*            >


<!-- ============================================================= -->
<!--                    PERSON'S NAME ELEMENTS (BIBLIOGRAPHIC)     -->
<!-- ============================================================= -->


<!--                    STRING NAME ELEMENTS                       -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        the <string-name> element                  -->
<!ENTITY % string-name-elements 
                        " | %person-name.class;"                     >


<!--                    NAME OF PERSON (UNSTRUCTURED)              -->
<!--                    Wrapper element for personal names where the
                        stricter format of the <name> element cannot
                        be followed. This is a very loose element,
                        allowing data characters, generated text,
                        and any or all of the naming elements.
                        Authoring or Conversion Note: Use this
                        element if the name parts are unknown or 
                        untagged.                                  -->
<!ELEMENT  string-name  (#PCDATA %string-name-elements;)*            >


<!--                    NAME OF PERSON (STRUCTURED)                -->
<!--                    Wrapper element for personal names.
                        Authoring or Conversion Note: If the name
                        parts are unknown or untagged, names should
                        be placed within the <string-name> element. 
                                                                   -->
<!ELEMENT  name         (surname, given-names?, prefix?, suffix?)    >
<!--         name-style Used for choosing an inversion algorithm or
                        for sorting or other processing functions.  The
                        three values and approximate meanings are:
                        Value     Display          Sort/Inversion
                        western   given family     family given
                        eastern   family given     family given
                        islensk   given patronymic given, patronymic
                                                                   -->
<!ATTLIST  name
             name-style (western | eastern | islensk)      "western" >


<!--                    SURNAME ELEMENTS                           -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <surname>                                
                        Design Note: This PE begins with an OR
                        bar because %just-rendition; begins with an
                        OR bar.                                    -->
<!ENTITY % surname-elements
                        "%just-rendition; "                          >


<!--                    SURNAME                                    -->  
<!--                    The surname of an individual.  If there is
                        only one name, for example, "Cher" or
                        "Pele", that is considered to be a surname
                        for consistency purposes.                  -->
<!ELEMENT  surname      (#PCDATA %surname-elements;)*                >
<!ATTLIST  surname
             %surname-atts;                                          >


<!--                    GIVEN (FIRST) NAMES ELEMENTS               -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <given-names>                            -->
<!ENTITY % given-names-elements
                        "%just-rendition;"                           >


<!--                    GIVEN (FIRST) NAMES                        -->
<!--                    Includes all given names for a person, such 
                        as the first name, middle names, maiden 
                        name if used as part of the married name, 
                        etc.)                                      -->
<!ELEMENT  given-names  (#PCDATA %given-names-elements;)*            >
<!ATTLIST  given-names
             %given-names-atts;                                      >


<!--                    PREFIX ELEMENTS                            -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <prefix>  
                        Design Note: This PE begins with an OR
                        bar because %just-rendition; begins with an
                        OR bar.                                    -->
<!ENTITY % prefix-elements
                        "%just-rendition;"                           >


<!--                    PREFIX                                     -->
<!--                    Honorifics or other qualifiers that usually 
                        precede the surname, for example,  Professor, 
                        Rev., President, Senator, Dr., Sir, The 
                        Honorable, et al.                          -->
<!ELEMENT  prefix       (#PCDATA %prefix-elements;)*                 >



<!--                    SUFFIX ELEMENTS                            -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <suffix>
                        Design Note: This PE begins with an OR bar,
                        it is inside %just-rendition;              -->
<!ENTITY % suffix-elements
                        "%just-rendition;"                           >


<!--                    SUFFIX                                     -->
<!--                    Text used as a suffix to a person's name, for
                        example: Sr. Jr. III, 3rd                  -->
<!ELEMENT  suffix       (#PCDATA %suffix-elements;)*                 >


<!-- ============================================================= -->
<!--                    EXTERNAL LINK ELEMENTS                     -->
<!-- ============================================================= -->


<!--                    EXTERNAL LINK ELEMENTS                     -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        an <ext-link>  
                        Design Note: All inline mixes begin with an
                        OR bar, but since %link-elements; is an inline
                        mix, the OR bar is already there.          -->
<!ENTITY % ext-link-elements
                        "%link-elements;"                            >


<!--                    EXTERNAL LINK                              -->
<!--                    Link to an external file, such as Medline, 
                        Genbank, etc.  Linking may be accomplished
                        using the XLink linking attributes.        -->
<!ELEMENT  ext-link     (#PCDATA %ext-link-elements;)*               >
<!--         ext-link-type 
                        Type of external link. Use this attribute
                        if the type of external link is one of the
                        ones below or another named type.
                        Suggested values include:
                            aoi         Astronomical Object Identifier 
                            doi         Digital Object Identifier
                            ec          Enzyme nomenclature - see
                              http://www.chem.qmw.ac.uk/iubmb/enzyme/
                            email       An email message
                            ftp         File transfer protocol
                            gen         GenBank identifier
                            genpept     Translated Protein-encoding
                                        sequence Database
                            highwire    HighWire press intrajournal 
                            medline     Medline or pubmed id
                            pdb         Protein data bank. See 
                                        http://www.rcsb.org/pdb/
                            pgr         Plant gene register. See
                                        http://www.tarweed.com/pgr/
                            pir         Protein Information Resource
                                        see http://pir.georgetown.edu
                            pirdb       Protein Information Resource 
                                        see http://pir.georgetown.edu
                            pmc         Used to link between articles  
                                        in PubMed Central access is 
                                        PMID
                            sprot       Swiss-Prot. See
                                    http://www.ebi.ac.uk/swissprot/
                            uri         Website or web service    
             id         Unique identifier so the element may be
                        referenced 
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename                -->
<!ATTLIST  ext-link
             %ext-link-atts;                                         >


<!-- ============================================================= -->
<!--                    STRUCTURAL ELEMENTS                        -->
<!-- ============================================================= -->


<!--                    ATTRIBUTION ELEMENTS                       -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        an attribution                          
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-phrase; is an 
                        inline mix, the OR bar is already there.   -->
<!ENTITY % attrib-elements
                        "%emphasized-text;"                          >
             

<!--                    ATTRIBUTION                                -->
<!--                    Source, author, formal thanks, or other 
                        information (other than copyright material)
                        concerning the origins of an extract, a poem
                        <verse-group> or similar element.
                        Formatting Note: Typically displayed on 
                        a separate line (or lines) following the 
                        material it concerns, inheriting that
                        material's margins.                        --> 
<!ELEMENT  attrib       (#PCDATA %attrib-elements;)*                 >
             

<!--                    PRICE                                      -->
<!--                    Sale price of a work, typically a book or
                        software package that is being reviewed    --> 
<!ELEMENT  price        (#PCDATA | %emphasis.class;)*                >


<!--                    STRUCTURAL TITLE ELEMENTS                  -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        the <title> element  
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-phrase; is an 
                        inline mix, the OR bar is already there.   -->
<!ENTITY % struct-title-elements 
                        "%simple-phrase; | %break.class;"            > 


<!--                    TITLE                                      -->
<!--                    Heading or title for a structural element
                        such as a Section, Figure, Boxed Text, etc.-->
<!ELEMENT  title        (#PCDATA %struct-title-elements;)*           >


<!--                    LABEL ELEMENTS                             -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        the <label> element                        -->
<!ENTITY % label-elements 
                        "| %emphasis.class; | %inline-display.class; | 
                         %inline-math.class; | %subsup.class;"       >


<!--                    LABEL OF A FIGURE, REFERENCE, ETC.         -->
<!--                    The number and any prefix word that comes
                        before, for example, the caption of a Figure,
                        such as "Figure 3." or "Exhibit 2.".  This
                        element can be used to preserve the prefix 
                        number or label of an element, for example
                        for a reference or citation "25." or
                        "[Lapeyre 2002]". This can be useful when
                        reconstructing untagged cross references.  -->                        
<!ELEMENT  label        (#PCDATA %label-elements;)*                  >


<!-- ============================================================= -->
<!--                    RELATED ARTICLE ELEMENTS                   -->
<!-- ============================================================= -->


<!--                    RELATED ARTICLE ELEMENTS                   -->
<!--                    Elements allowed inside <related-article>  -->
<!ENTITY % related-article-elements 
                        "| %emphasis.class; |%references.class; | 
                         %subsup.class;"                             >


<!--                    RELATED ARTICLE INFORMATION                -->
<!--                    Wrapper element, used as a container for 
                        text links to a related article, possibly 
                        accompanied by a very brief description
                        such as "errata (correction)".
                        Remarks: This element is slightly overloaded
                        in that it has 2 uses, one inside the article
                        metadata to name one or more related articles
                        and as part of the link class, which can
                        occur many places in textual content.
                        This allows all such references, to 
                        companion articles within the same journal,
                        to a previous part of a multi-part article,
                        to a news item that summarizes the article,
                        to the article for which this article is
                        a correction or addendum, etc. wherever 
                        these occur in the article.                -->
<!ELEMENT  related-article
                        (#PCDATA %related-article-elements;)*        >
<!--         id         Unique identifier so the element may be
                        referenced
             alt-form-of
                        Exactly like the "alt-form-of" attribute
                        used with <graphic>, this is an IDREF
                        attribute which points to the ID of another
                        <related-article> in the same document
                         rather than to an external file.
             related-article-type
                        This attribute can take any text value,
                        suggested values include:
                          addendum      Additional material for an
                                        article, generated too late
                                        to be added to the main text
                          commentary-article   
                                        Used in an commentary or
                                        editorial to link to the 
                                        article on which it is
                                        commenting
                          companion     Used in an article to link 
                                        to a companion (related
                                        or sibling article) 
                          corrected-article
                                        Used in a correction to link 
                                        to the article being 
                                        corrected. Sometimes called
                                        erratum.
                          in-this-issue Related article in the same
                                        journal issue
                          letter        A letter to the publication
                                        or a reply to such a
                                        letter
                          commentary    Used in an article to link 
                                        to its associated commentary
                                        or editorial 
                          correction-forward
                                        Used in an article to link
                                        forward to its associated 
                                        correction (rarely used)
                          partial-retraction  Partial retraction of 
                                      previously published material
                          retracted-article
                                        Used in a retraction to link 
                                        to the article being retracted
                          retraction-forward   
                                        Used in an article to link
                                        forward to its associated 
                                        retraction (rare)
             vol        Volume of the journal in which the related
                        article exists.  The scope is limited to
                        the journal; in which the current article
                        resides.
             page       Page number of the related article. Scope
                        is limited to the volume of the journal in 
                        which the current article resides. The 
                        values should be a first page or a page 
                        range.
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename.               -->
<!ATTLIST  related-article
             %related-article-atts;                                  >


<!-- ============================================================= -->
<!--                    FRONT MATTER/BACK MATTER ELEMENTS          -->
<!-- ============================================================= -->


<!--                    ACKNOWLEDGMENTS MODEL                      -->
<!--                    Content model for the <ack> element        -->
<!ENTITY % ack-model    "%sec-opt-title-model;"                      > 


<!--                    ACKNOWLEDGMENTS                            -->
<!ELEMENT  ack          %ack-model;                                  >
<!--         id         Unique identifier so the element may be
                        referenced                                
             content-type   
                        Identification of the subject, type of
                        content, or reason that this word or phrase
                        is considered semantically special, as a 
                        means of preserving the semantic intent of 
                        the original tagging.                      -->
<!ATTLIST  ack                                
             id         ID                                 #IMPLIED
             content-type
                        CDATA                              #IMPLIED  >


<!--                    BIOGRAPHY MODEL                            -->
<!--                    Content model for the <bio> element        -->
<!ENTITY % bio-model    "(title?, (%just-para.class;)+ ) "           > 


<!--                    BIOGRAPHY                                  -->
<!--                    Short biography of a person, usually the
                        author                                     
                        Authoring Note:  The "xlink:href" attribute
                        may be used to point to a graphic of the
                        author or to his/her website, etc.         -->
<!ELEMENT  bio          %bio-model;                                  >      
<!--         id         Unique identifier so the element may be
                        referenced 
             rid        Points to the identifier of an author or
                        authors                               
             xlink:href Provides an address or identifier of the
                        object to which the link points, for
                        example a URI or a filename.               -->
<!ATTLIST  bio
             %bio-atts;                                              >


<!--                    NOTES MODEL                                -->
<!--                    Content model for the <notes> element      -->
<!ENTITY % notes-model  "%sec-opt-title-model;"                      > 
             

<!--                    NOTES                                      -->
<!--                    A container element for the notes that may
                        appear at the end of an Article or at the 
                        end of a Table.  For example, a typical
                        end-of-article note is a "Note in Proof". 
                        A Note in Proof contains late-breaking news 
                        items or other material produced while the 
                        article was  being typeset or was otherwise 
                        in production, that therefore happened too 
                        late to be included in the text of the 
                        article. This is typically NOT peer-reviewed
                        content and citations to other material is
                        usually just integrated into the text, not
                        listed separately in a References List.    -->
<!ELEMENT  notes        %notes-model;                                >      
<!--         id         Unique identifier so the element may be
                        referenced                                 
             notes-type To identify the type of note, if the type can
                        be/has been identified, for example,
                        "note-in-proof"                            -->                     
<!ATTLIST  notes
             %notes-atts;                                            >


<!-- ============================================================= -->
<!--                    ACCESSIBILITY ELEMENTS                     -->
<!-- ============================================================= -->


<!--                    ALTERNATE TITLE TEXT FOR A FIGURE, ETC.    -->
<!--                    Short phrase used to display or pronounce 
                        as an alternative to providing the full
                        graphic for accessibility display or 
                        graphic-limited websites or devices. For 
                        example, <alt-text> may be used to display 
                        "behind" a figure or graphic.   
                        Authoring and Conversion Note: Not to be used
                        as a replacement for <caption>.            -->
<!ELEMENT  alt-text     (#PCDATA)                                    >
<!--         id         Unique identifier so the element may be
                        referenced                                 
             xml:lang   The language in which the value of the
                        element is expressed.  Recommended best 
                        practice is to use values as defined in
                        RFC 1766, typically 2-letter language
                        codes such as "FR" (French), "EN" (English),
                        and "DE" (German). These values are NOT
                        case sensitive, so "EN" = "en". The values
                        may include hyphenated differentiations such 
                        as "EN-AU" (Australian English) and "EN-US"
                        (United States English).                   -->             
<!ATTLIST  alt-text
             id         ID                                 #IMPLIED  
             xml:lang   NMTOKEN                            #IMPLIED  > 


<!--                    LONG DESCRIPTION ELEMENTS                  -->
<!--                    Elements to be mixed with data characters
                        inside the <long-desc> element             -->
<!ENTITY % long-desc-elements
                        " "                                          >


<!--                    LONG DESCRIPTION                           -->
<!--                    Description or summary of the content of a 
                        graphical object, table, or textual object
                        such as a text box, used by some systems to
                        make the object accessible, even to people
                        or systems that cannot read/see/display the
                        object.                                  
                        Authoring and Conversion Note: Not to be used
                        as a replacement for <caption>.            -->
<!ELEMENT  long-desc    (#PCDATA %long-desc-elements;)*              >
<!--         id         Unique identifier so the element may be
                        referenced                                 
             xml:lang   The language in which the value of the
                        element is expressed.  Recommended best 
                        practice is to use values as defined in
                        RFC 1766, typically 2-letter language
                        codes such as "FR" (French), "EN" (English),
                        and "DE" (German). These values are NOT
                        case sensitive, so "EN" = "en". The values
                        may include hyphenated differentiations such 
                        as "EN-AU" (Australian English) and "EN-US"
                        (United States English).                   -->                 
<!ATTLIST  long-desc
             id         ID                                 #IMPLIED  
             xml:lang   NMTOKEN                            #IMPLIED  > 


<!--                    DEFINITION LIST: DEFINITION MODEL          -->
<!--                    Content model for the <def> element        -->
<!ENTITY % def-model    "((%just-para.class;)+ )"                    > 

  
<!--                    DEFINITION LIST: DEFINITION                -->
<!--                    Used in two senses:
                        1) The definition, description, or other
                        explanation of the word, phrase, or picture
                        of a 2-part or definition list
                        2) The definition or expansion of an
                        abbreviation or acronym <abbrev>           -->
<!ELEMENT  def          %def-model;                                  >
<!--         id         Unique identifier so the element may be
                        referenced 
             rid        Points to the identifier of a term,
                        so that a term and definition may be linked
                                                                   -->
<!ATTLIST  def                                
             rid        IDREFS                             #IMPLIED 
             id         ID                                 #IMPLIED  >


<!-- ============================================================= -->
<!--                    CUSTOMIZED METADATA ELEMENTS               -->
<!-- ============================================================= -->


<!--                    CUSTOMIZED METADATA WRAPPER MODEL          -->
<!--                    Content model for the <custom-meta-wrap> 
                        element                                    -->
<!ENTITY % custom-meta-wrap-model
                        "(custom-meta+)"                             > 


<!--                    CUSTOMIZED METADATA WRAPPER                -->
<!--                    Some DTDs and schemas allow for metadata
                        above and beyond that which can be specified
                        by this DTD. This element is a wrapper 
                        element used to contain all these additional
                        metadata elements.                         -->
<!ELEMENT  custom-meta-wrap
                        %custom-meta-wrap-model;                     >


<!--                    CUSTOMIZED METADATA MODEL                  -->
<!--                    Content model for the <custom-meta> element-->
<!ENTITY % custom-meta-model
                        "(meta-name, meta-value)"                    > 


<!--                    CUSTOM METADATA                            -->
<!--                    Some DTDs and schemas allow for metadata
                        above and beyond that which can be specified
                        by this DTD. This element is used to capture
                        metadata elements that have not been defined
                        explicitly in the models for this DTD, so 
                        that the intellectual content will not be lost.
                          Remarks:  The <custom-meta> element allows 
                        for an infinite number of name/value pairs,
                        with few constraints on the length or
                        content of the value. This element will 
                        probably be used for special cases, product-
                        specific material, or other unusual
                        metadata, for example the journal-history
                        information preserved in at least one
                        publisher's DTD.                           -->
<!ELEMENT  custom-meta  %custom-meta-model;                          >


<!--                    METADATA DATA NAME ELEMENTS                -->
<!--                    Elements that may be used, along with data
                        characters, inside the <meta-name> element 
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-phrase; is an 
                        inline mix, the OR bar is already there.   -->
<!ENTITY % meta-name-elements
                        "%simple-phrase;"                            > 


<!--                    METADATA DATA NAME FOR CUSTOM METADATA     -->
<!--                    Some DTDs and schemas allow for metadata
                        above and beyond that which can be specified
                        by this DTD. The <custom-meta> element
                        allow for an infinite number of name/value
                        pairs, with few constraints on the length or
                        content of the value. This element contains
                        the name of the metadata field.            -->
<!ELEMENT  meta-name    (#PCDATA %meta-name-elements;)*              >


<!--                    METADATA DATA VALUE ELEMENTS               -->
<!--                    Elements that may be used, along with data
                        characters, inside the <meta-value> element 
                        Design Note: All inline mixes begin with an
                        OR bar, but since %simple-phrase; is an 
                        inline mix, the OR bar is already there.   -->
<!ENTITY % meta-value-elements
                        "%simple-phrase;"                            > 
   

<!--                    METADATA DATA VALUE FOR CUSTOM METADATA    -->
<!--                    Some DTDs and schemas allow for metadata
                        above and beyond that which can be specified
                        by this DTD. The <custom-meta> element
                        allow for an infinite number of name/value
                        pairs, with few constraints on the length or
                        content of the value. This element contains
                        the value of the metadata field that is named
                        by the <meta-name> element.                -->
<!ELEMENT  meta-value   (#PCDATA %meta-value-elements;)*             >



<!-- ============================================================= -->
<!--                    GENERATED TEXT OR PUNCTUATION              -->
<!-- ============================================================= -->


<!--                   X TEXT ATTRIBUTES                           -->
<!--                   Attributes for the element <x>              -->
<!ENTITY % x-atts
              "xml:space (default | preserve)     #FIXED 'preserve'" > 


<!--                    X ELEMENTS                                 -->
<!--                    Elements for use inside the <x> element    -->
<!ENTITY % x-elements   " "                                          > 


<!--                    X - GENERATED TEXT AND PUNCTUATION         -->
<!--                    A container element to hold punctuation or
                        other generated text, typically when 1) an
                        archive decides not to have any text
                        generated and thus to pre-generate such 
                        things as commas or semicolons between 
                        keywords or 2) when an archive receives text
                        with <x> tags embedded and wishes to retain
                        them.
                          Remarks: This element is called "x" for
                        historical reasons, since DTDs that use an
                        element for generated punctuation have
                        typically called it that.                  -->
<!ELEMENT  x            (#PCDATA %x-elements;)*                      >
<!--         xml:space  Request that, when printing or displaying
                        this element, all white space such as tabs
                        and spaces and line breaks be preserved.   -->
<!ATTLIST  x
             %x-atts;                                                >


<!-- ================== End Common (Shared) Elements Module ====== -->
     
