866-868 doesn't parse information into specific subfields, since it's considered a free text field. If you want to separately identify the pieces of information you use the parsed fields (863-865). That's why originally changes to MARC for holdings didn't do much specific subfield coding in fields 866-868. Rebecca Rebecca Squire Guenther 215 W. 75th St. Apt. 16H New York, N.Y. 10023 703-298-0157 [log in to unmask] http://www.meetyourdata.com On Thu, Feb 28, 2019 at 7:51 AM Hostage, John <[log in to unmask]> wrote: > Subfield $o is valid in holdings fields 853/855 and 863/865, but not in > 866/868. It seems like it should be valid in order to correctly convert > from paired fields to textual fields. Any ideas on why it wasn’t made > valid? > > > > ------------------------------------------ > > John Hostage > > Senior Continuing Resources Cataloger > > Harvard Library--Information and Technical Services > > Langdell Hall 194 > > Harvard Law School Library > > Cambridge, MA 02138 > > [log in to unmask] > > +(1)(617) 495-3974 (voice) > > +(1)(617) 496-4409 (fax) > ISNI 0000 0000 4028 0917 > > >