The identifier of a publication, such as a related journal article that is listed within a Citation (<citation>) inside an article’s Reference List (Bibliographic Reference List) (<ref-list>).
The pub-id-type attribute is used either to identify the type of identifier, or to name the authority, organization, or system that defined this identifier. Valid Types include: coden, DOI, medline, pii, the publisher, etc.
Text, numbers, or special characters
<article>
<front>...
</front>
<body>
...
</body>
<back>...
<ref-list>...
<ref id="B8">
<label>8</label>
<citation>
<name><surname>Weissert</surname>
<given-names>W</given-names></name>
<name><surname>Wan</surname>
<given-names>T</given-names></name>
<name><surname>Livieratos</surname>
<given-names>B</given-names></name>
<name><surname>Katz</surname>
<given-names>S</given-names></name>
<article-title>Effects and costs of day-care services
for the chronically ill: a randomized
experiment.</article-title>
<source>Medical Care</source>
<volume>18</volume>
<year>1980</year>
<fpage>567</fpage>
<lpage>584</lpage>.
<pub-id pub-id-type="pmid">6772889</pub-id>
</citation></ref>
...
references.ent