Typically, the year of publication for a book or other work, but also the year “historical” events in a publishing cycle occurred, for example, the year a manuscript was last updated.
The <year> element is used in two contexts: as a part of the metadata concerning book or book component (such as a chapter), and as part of a description of a cited work inside a bibliographic reference (<citation>) element.
Conversion Note: When possible, the year should be expressed as a 4-digit number, for example, “1776”, “1924”, or “0042”.
<!ELEMENT year (#PCDATA) >
Text, numbers, or special characters
<citation> Citation; <date> Date; <pub-date> Publication Date; <related-article> Related Article Information; <string-date> Date as a String
...<ref-list>
<title>References</title>
<ref id="bid.41">
<label>1</label>
<citation>
<person-group>
<name><surname>Olson</surname><given-names>M</given-names></name>
<name><surname>Hood</surname><given-names>L</given-names></name>
<name><surname>Cantor</surname><given-names>C</given-names></name>
<name><surname>Botstein</surname><given-names>D</given-names></name>
</person-group>
<article-title>A common language for physical mapping
of the human genome</article-title>
<source>Science</source>
<year>1989</year>
<volume>245</volume>
<issue>4925</issue>
<fpage>1434</fpage>
<lpage>1435</lpage>
<pub-id pub-id-type="pmid">2781285</pub-id>
</citation>
</ref>
</ref-list>...
common.ent