A container element that holds unstructured text within an otherwise element-structured bibliographic reference (<element-citation> or <mixed-citation>); therefore, this is not necessarily a comment in the formal sense of commentary. In an unstructured bibliographic reference, this textual material would merely be a mixture of text, numbers, or special characters, such as punctuation, and not marked with tags at all.
The element <comment> is used to contain additional information about a citation that is not appropriate in any of the other, named, information types.
Since in the Journal Archiving Tag Set, the model for <mixed-citation> is a loose model with text, numbers, and special characters, such as punctuation, allowed everywhere, this element will rarely be needed. The <comment> element has been defined here largely for the sake of conversion, to preserve unusual bits of semantic markup when translating from other tag sets. Typical comments might include:
<comment>[Abstract]</comment> <comment>translated from Russian</comment>
Conversion Note: The <comment> element should be used to mark substantive text only; it should not be used to mark punctuation that occurs between elements.
<!ELEMENT comment (#PCDATA %comment-elements;)* >
(#PCDATA | email | ext-link | uri | inline-supplementary-material | related-article | related-object | hr | bold | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | alternatives | inline-graphic | private-char | chem-struct | inline-formula | tex-math | mml:math | abbrev | milestone-end | milestone-start | named-content | styled-content | fn | target | xref | sub | sup | x)*
Any combination of:
<element-citation>, <mixed-citation>, <nlm-citation>, <product>, <related-article>, <related-object>
In an element-style bibliographic reference (punctuation and spacing removed):
... <ref> <element-citation publication-type="commun"> <person-group> <name><surname>Nightingale</surname> <given-names>Florence</given-names></name> 115 Park Street, W, [London, GB] </person-group> <source>Letter to: Marquis Townshend</source> <year>1864</year> <month>Jul</month> <day>27</day> <size units="leaf">4 leaves</size> <comment>Located at: Modern Manuscripts Collection, History of Medicine Division, National Library of Medicine, Bethesda, MD; MS F 179</comment> <annotation><p>Nightingale responds to Townshend’s request on behalf of a Mrs. Montague for funds to support old nurses</p></annotation> </element-citation> </ref> ...