Harvard policy until further notice: copy the 337 and 338 fields describing the resource in hand from the bibliographic record into the holdings record. Do not copy field 336 (Content Type) into the holdings record.From: https://wiki.harvard.edu/confluence/pages/viewpage.action?pageId=71894041
The codes (‡b) in the 33x fields should not be removed when encountered, but should not be added to new original RDA records (unless using the template created by Honor Moody, which includes them).
Per RDA 184.108.40.206 alternative B, add 336s only when other formats are SUBSTANTIVE, as one would add a 006 under AACR2. If an additional 336 is added, add a 006.
AACR2 and pre-AACR2 copy frequently has 33Xs. If they are in a non-RDA bibliographic record, the 337 and 338 fields may also be included in the attached holding record.