Used for any kind of internal article referencing
This element may be used to reference anything that has an id attribute (an attribute of type id). This single element takes the place of the many named types of references (such as figure references, table references, and footnote references) that are common in many journal Tag Sets.
The ref-type attribute (of the <xref> element) can be used to preserve information concerning what type of element is being pointed to by the cross-reference.
Display/Formatting Note: The content of the reference (if present) will be displayed as the link.
<!ELEMENT xref (#PCDATA %xref-elements;)* >
Any combination of:
<abbrev> Abbreviation or Acronym; <abbrev-journal-title> Abbreviated Journal Title; <addr-line> Address Line; <aff> Affiliation; <alt-title> Alternate Title; <anonymous> Anonymous; <article-title> Article Title; <attrib> Attribution; <bold> Bold; <chem-struct> Chemical Structure (Display); <citation> Citation; <collab> Collaborative (Group) Author; <comment> Comment in a Citation; <conf-acronym> Conference Acronym; <conf-loc> Conference Location; <conf-name> Conference Name; <conf-num> Conference Number; <conf-sponsor> Conference Sponsor; <conf-theme> Conference Theme; <contract-num> Contract Number; <contract-sponsor> Contract Sponsor; <contrib> Contributor; <contrib-group> Contributor Group; <copyright-statement> Copyright Statement; <corresp> Correspondence Information; <def-head> Definition List: Definition Head; <degrees> Degree(s); <disp-formula> Formula, Display; <edition> Edition, Cited; <email> Email Address; <etal> Et Al.; <ext-link> External Link; <fax> Fax Number: in an Address; <font> Font; <given-names> Given (First) Names; <gov> Government Report, Cited; <grant-num> Grant Number; <grant-sponsor> Grant Sponsor; <history> History: Document History; <inline-formula> Formula, Inline; <inline-supplementary-material> Inline Supplementary Material; <institution> Institution Name: in an Address; <issue> Issue Number; <issue-title> Issue Title; <italic> Italic; <journal-subtitle> Journal Subtitle (Full); <journal-title> Journal Title (Full); <kwd> Keyword; <label> Label (of a Figure, Reference, Etc.); <meta-name> Metadata Data Name for Custom Metadata; <meta-value> Metadata Data Value for Custom Metadata; <monospace> Monospace Text (Typewriter Text); <named-content> Named Special (Subject) Content; <on-behalf-of> On Behalf of; <overline> Overline; <p> Paragraph; <patent> Patent Number, Cited; <phone> Phone Number: in an Address; <prefix> Prefix; <preformat> Preformatted Text; <product> Product Information; <publisher-loc> Publisher’s Location; <publisher-name> Publisher’s Name; <related-article> Related Article Information; <role> Role or Function Title of Contributor; <sans-serif> Sans Serif; <sc> Small Caps; <self-uri> URI for This Same Article Online; <series> Series; <series-text> Series Text: Header Text to Describe; <series-title> Series Title; <sig> Signature; <sig-block> Signature Block; <source> Source; <speaker> Speaker; <std> Standard, Cited; <strike> Strike Through; <string-date> Date as a String; <string-name> Name of Person (Unstructured); <sub> Subscript; <subject> Subject Grouping Name; <subtitle> Article Subtitle; <suffix> Suffix; <sup> Superscript; <supplement> Supplement Information; <surname> Surname; <target> Target of an Internal Link; <td> Table Data Cell (XHTML table model); <term> Definition List: Term; <term-head> Definition List: Term Head; <th> Table Header Cell (XHTML table model); <title> Title; <trans-source> Translated Source; <trans-subtitle> Translated Subtitle; <trans-title> Translated Title; <underline> Underline; <uri> Uniform Resource Indicator (URI); <verse-line> Line of a Verse; <volume> Volume Number; <volume-id> Volume Identifier; <xref> X(cross) Reference
<article>
<front>
...
</front>
<body>...
<p>Geriatric day hospitals developed rapidly in the United Kingdom in the
1960s as an important component of care provision. ...
Although there is considerable descriptive literature on day hospital
care,<xref ref-type="bibr" rid="B1">1</xref> concern has been expressed
that evidence for effectiveness is equivocal and that day hospital care
is expensive.<xref ref-type="bibr" rid="B2">2</xref> ...</p>...
</body>
<back>...
<ref-list>
<ref id="B1"><label>1</label>
<citation citation-type="book">
<collab>Research Unit of the Royal
College of Physicians and British
Geriatric Society</collab>
<source>Geriatric day hospitals: their role
and guidelines for good
practice</source>
<publisher-loc>London</publisher-loc>
<publisher-name>RCP</publisher-name>
<year>1994</year>
</citation>
</ref>
<ref id="B2">...</ref>
...
</ref-list>...
</back>
</article>
link.ent