obituarysee @article-type
Object Identifier Attributes parameter entitysee %object-id-atts;
object typesee @object-id-type
obsolete termsee @term-status
On Behalf of Content Elements parameter entitysee %on-behalf-of-elements;
on-leave (contributor is on sabbatical or other leave of absence.)see @fn-type
online datesee @date-type
online location identifiersee <elocation-id>
online versionsee <self-uri>
ontologysee @vocab
op citsee Abbreviated Citations
open accesssee <license>
open access fee informationsee <funding-group>
Open Access Model parameter entitysee %open-access-model;
orationsee @article-type
ORCIDsee <contrib-id>see @contrib-id-type
ordersee <named-content>
orderedsee @list-type
ordered listsee <list>
ordinals in citationssee Tagging Ordinal Numbers
Ordinary Symbols for MathML parameter entitysee %ISOamso;
organizationsee <aff>
organizational addresssee <address>
organizational authorsee <collab>
organization namesee <collab>see <institution>
originationsee <source>
other information, concerning an authorsee <author-comment>
outlinesee <abstract>
outside flowsee <boxed-text>
owner, copyrightuse <copyright-holder>