This is how I would interpret it. I would count any time you're the A code as PIC time. If you're an MP flying with a more experienced MP (who has the A code), you're time would probably be best described as Second In Command (SIC) time in FAA terms. However, if I were an MP flying with an IP/EP, say on a checkride, I would log PIC even though the EP would have the A code. This is because in the civilian world, you log your checkrides as PIC.

The Air Force has primary, secondary and other time. As an FPC, primary and secondary time will obviously never be PIC time. However, as an MP with the A code, primary and secondary time is always PIC. I would never consider other time as PIC or even SIC. A shadey area would be if an IP/EP with the A code is in the jumpseat logging "other" time and IP/EP time. I would feel I was cheating the system logging PIC time in the jumpseat while two other pilots were at the controls, but technically, you are the IP/EP and the FAA/airlines would probably not having a problem with you counting that time as PIC time. As a copilot, interpreting time is pretty easy because none of it's PIC time. I count my primary/secondary time towards my total time/turbine time/multiengine time/etc which is combined with the civilian time I have.

A lot of it is interpretation because the Air Force and FAA's definition of flight time are two different things. The best thing to do is just hand an airline a HARMS printout and have them interpret it, but I would still use an electronic or paper logbook for your own records, just in case the Air Force's HARMS system takes a dump and loses all your time. While logging it myself, I would log the time the way the FAA would expect to see it (PIC, SIC, etc...).