<!-- ============================================================= -->
<!--  MODULE:    Link Element Classes                              -->
<!--  VERSION:   3.0                                               -->
<!--  DATE:      Feb 2008                                          -->
<!--                                                               -->
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<!-- ============================================================= -->
<!--                    PUBLIC DOCUMENT TYPE DEFINITION            -->
<!--                        TYPICAL INVOCATION                     -->
<!--
"-//NLM//DTD Archiving and Interchange DTD Suite Link Class Elements v3.0 20080202//EN"
     Delivered as file "link3.ent"                                 -->
<!-- ============================================================= -->


<!-- ============================================================= -->
<!-- SYSTEM:     Archiving and Interchange DTD Suite               -->
<!--                                                               -->
<!-- PURPOSE:    Names all elements in the link class. These are   --> 
<!--             elements that are links (internal or external)    -->
<!--             by definition, such as URLs <uri> and             -->
<!--             Cross(X)-references <xref>.                       -->
<!--                                                               -->
<!-- CONTAINS:   1) Default definitions of the link classes        -->
<!--             2) Default definitions for attribute values       -->
<!--             3) Default definitions for attribute lists        -->
<!--             4) Models for the link class elements, first      -->
<!--             internal links then external links                -->
<!--             (alphabetically)                                  -->
<!--                                                               -->
<!--             (Note: Links make their links using the XLink     -->
<!--             global attributes. Many elements besides          -->
<!--             explicit links may be made into links using       -->
<!--             these attributes. Such elements are defined in    -->
<!--             the module appropriate to their use and are not   -->
<!--             listed here.)                                     -->
<!--                                                               -->
<!-- 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."                                    -->
<!--                                                               -->
<!-- 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      --> 
<!--                                                               -->
<!--             Suggestions for refinements and enhancements to   -->
<!--             the DTD suite should be sent in email to:         -->
<!--                 archive-dtd@ncbi.nlm.nih.gov                  -->
<!--                                                               -->
<!-- ============================================================= -->


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

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

     =============================================================
     Version 3.0                       (DAL/BTU) v3.0 (2007-10-31)
     
     Version 3.0 is the first non-backward-compatible release.
     In addition to the usual incremental changes, some
     elements and attributes have been renamed and/or remodeled
     to better meet user needs and to increase tag set consistency.
     All module change histories are available through the Tag Suite 
     web site at http://dtd.nlm.nih.gov. 

     Details on version 3.0 are available at 
           http://dtd.nlm.nih.gov/3.0.
  
  1. Updated public identifier to "v3.0 20080202//EN"              -->


<!-- ============================================================= -->
<!--                    DEFAULTS FOR ATTRIBUTE VALUES              -->
<!-- ============================================================= -->


<!--                    DEFAULT TYPE OF CROSS(X)-REFERENCE         -->
<!--                    Used to say to what the reference is pointing.
                        Values are, for example: Affiliation "aff", 
                        or Figure "fig".                           -->
<!ENTITY % ref-types    "aff | app | author-notes | bibr | 
                         boxed-text | chem | contrib | corresp | 
                         disp-formula | fig | fn | kwd | list | 
                         plate | scheme | sec | statement | 
                         supplementary-material | 
                         table | table-fn | 
                         other"                                      >


<!-- ============================================================= -->
<!--                    DEFAULTS FOR ATTRIBUTE LISTS               -->
<!-- ============================================================= -->


<!--                    FOOTNOTE ATTRIBUTES                        -->
<!--                    Attribute list for Footnote element        -->
<!ENTITY % fn-atts
             "id         ID                                #IMPLIED  
              symbol     CDATA                             #IMPLIED 
              fn-type    CDATA                             #IMPLIED  
              xml:lang   NMTOKEN                           #IMPLIED" > 


<!--                    INLINE SUPPLEMENTARY MATERIAL              -->
<!--                    Attribute list for inline supplementary 
                        material                                   -->
<!ENTITY % inline-supplementary-material-atts
             "id        ID                                #IMPLIED
              content-type
                        CDATA                             #IMPLIED
              mimetype  CDATA                             #IMPLIED 
              mime-subtype
                        CDATA                             #IMPLIED
              %might-link-atts;"                                     >                                    


<!--                    TARGET ATTRIBUTES                          -->
<!--                    Attribute list for <target> element        -->
<!ENTITY % target-atts
             "id        ID                                #REQUIRED
              target-type
                        CDATA                             #IMPLIED"  >


<!--                    X(CROSS) REFERENCE ATTRIBUTES              -->
<!--                    Attribute list for cross references        -->
<!ENTITY % xref-atts
             "id         ID                               #IMPLIED
              ref-type   (%ref-types;)                    #IMPLIED 
              rid        IDREFS                           #IMPLIED"  >


<!-- ============================================================= -->
<!--                    INTERNAL LINKS                             -->
<!-- ============================================================= -->


<!--                    FOOTNOTE MODEL                             -->
<!--                    Content model for Footnote <fn>            -->
<!ENTITY % fn-model     "(label?, (%just-para.class;)+ )"            > 


<!--                    FOOTNOTE                                   -->
<!--                    Additional information concerning material in
                        a particular location in the text. This
                        material is not considered to be part of the 
                        body of the text, but in addition to or a 
                        commentary on the body.
                        Details at: 
                        http://dtd.nlm.nih.gov/archiving/tag-library/3.0/index.html?elem=fn
                        http://dtd.nlm.nih.gov/publishing/tag-library/3.0/index.html?elem=fn
                        http://dtd.nlm.nih.gov/articleauthoring/tag-library/3.0/index.html?elem=fn
                        http://dtd.nlm.nih.gov/book/tag-library/3.0/index.html?elem=fn
                                                                   -->
<!ELEMENT  fn           %fn-model;                                   >
<!ATTLIST  fn
             %fn-atts;                                               > 


<!--                    TARGET ELEMENTS                            -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        a <target>  
                        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 % target-elements
                        "%link-elements;"                            >


<!--                    TARGET OF AN INTERNAL LINK                 -->
<!--                    May be placed anywhere within textual 
                        material such as a paragraph to provide a
                        location (anchor) to which a cross reference
                        can point  
                        Details at: 
                        http://dtd.nlm.nih.gov/archiving/tag-library/3.0/index.html?elem=target
                        http://dtd.nlm.nih.gov/publishing/tag-library/3.0/index.html?elem=target
                        http://dtd.nlm.nih.gov/articleauthoring/tag-library/3.0/index.html?elem=target
                        http://dtd.nlm.nih.gov/book/tag-library/3.0/index.html?elem=target
                                                                   -->
<!ELEMENT  target       (#PCDATA %target-elements;)*                 >
<!ATTLIST  target
             %target-atts;                                           >


<!--                    X(CROSS) REFERENCE ELEMENTS                -->
<!--                    The elements that can be included along with
                        data characters inside the content model of
                        an <xref>  
                        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 % xref-elements
                        "%link-elements;"                            >

  
<!--                    X(CROSS) REFERENCE                         -->
<!--                    Used for any kind of internal article
                        referencing. The content of the reference 
                        (if present) will be displayed as the link.
                        This element may be used to point to any 
                        element that takes an "id" attribute.
                        The "ref-type" attribute may be used to name
                        the element or type of object to which the 
                        <xref> is pointing.
                        Details at: 
                        http://dtd.nlm.nih.gov/archiving/tag-library/3.0/index.html?elem=xref
                        http://dtd.nlm.nih.gov/publishing/tag-library/3.0/index.html?elem=xref
                        http://dtd.nlm.nih.gov/articleauthoring/tag-library/3.0/index.html?elem=xref
                        http://dtd.nlm.nih.gov/book/tag-library/3.0/index.html?elem=xref
                                                                   -->
<!ELEMENT  xref         (#PCDATA %xref-elements;)*                   >
<!ATTLIST  xref
             %xref-atts;                                             >


<!-- ============================================================= -->
<!--                    EXTERNAL LINKS                             -->
<!-- ============================================================= -->


<!--                    INLINE SUPPLEMENTARY MATERIAL ELEMENTS     -->
<!--                    Elements for use in the 
                        <inline-supplementary-material> element    -->
<!ENTITY % inline-supplementary-material-elements 
                        "| %access.class; | %address-link.class; | 
                         %emphasis.class; | 
                         %phrase-content.class; | %subsup.class;"    > 


<!--                    INLINE SUPPLEMENTARY MATERIAL              -->
<!--                    An in-text link to an external file that
                        provides supplementary information for
                        the document, for example, an audio clip
                        Details at: 
                        http://dtd.nlm.nih.gov/archiving/tag-library/3.0/index.html?elem=inline-supplementary-material
                        http://dtd.nlm.nih.gov/publishing/tag-library/3.0/index.html?elem=inline-supplementary-material
                        http://dtd.nlm.nih.gov/articleauthoring/tag-library/3.0/index.html?elem=inline-supplementary-material
                        http://dtd.nlm.nih.gov/book/tag-library/3.0/index.html?elem=inline-supplementary-material
                                                                   -->
<!ELEMENT  inline-supplementary-material
                        (#PCDATA 
                         %inline-supplementary-material-elements;)*  >
<!ATTLIST  inline-supplementary-material
             %inline-supplementary-material-atts;                    >


<!-- ================== End Link Class Module ==================== -->
