The values for the Declared Value list for the pub-id-type attribute.
The pub-id-type attribute names the type of identifier, or the organization or system that defined the identifier, for the identifier of the journal article or a cited publication. This attribute is used on the <article-id> element, which holds an identifier for the entire article. Also used on the <pub-id> element, which is an identifier for a publication cited in a bibliographic reference (<citation>).
<!ENTITY % pub-id-types "coden | doi | medline | other
| pii | pmid | publisher-id | sici" >common.ent