Kept a separate column - copilot/pic for when I was FO and flying. That way different companies could figure out, based on their requirements, how much pic or fo time I had.

For FAA requirements (ie consolidation) the company only tracks seat time. So you get full credit on 2 man crews, 2/3's on 3 man, and 1/2 on 4 man crews. So with 1000 hrs on type the company records show 700 hrs in type.

As Captain I log all time as PIC but make a note to indicate PF or PM status.