MFN_M02 and Staff Type

What field in the MFN_M02 message would dictate what the staff person is such as OT, PT, MD, DO, RN,….  Mckesson Star Folks are stating that the STF:4 field which is affectionately labeled “staff type” is where they place the Clinical Group. This is part of their base code. Any modification otherwise would be a customization.  In the particualar case I am dealing with, everyone has MD in that field……In my opinion, the clinical group should be placed into PRA:2 labeled Practitioner Group and Staff Type should be placed into STF:4.  Anybody have any insight????