[Groff] does mom understand refer %X field?

[Anton Shterenlikht]

The mom manual doesn't mention %X refer field:

http://www.schaffter.ca/mom/momdoc/refer.html#fields-quick

Does it mean mom will not understand, or ignore %X field?
I use for DOI information, e.g.

%X DOI: 10.1016/j.actamat.2010.03.013

Should I use %O for it if I want to use mom?

Thank you
Anton

P.S. I like this groff thing more and more!