In the example message in section 7.9.3 (for the CSU message type) there is  "note" which should be removed and if necessary addressed through changes to the spec.

Note:  The clinical trials section probably needs its own definition of OBR.  OBR-2&3 have condition rules indicating that the placer and filler numbers must be present in either the ORC or the OBR.  Since an ORC is not present, then these fields must be populated in the OBR.  My guess is that clinical trials aren't interested in the placer and filler number.