Contract4, As far as my legal understanding of EU-OPS goes, there is only one PIC, and thats the Commander of the aircraft. You cannot have both pilots of a two-crew aircraft claiming P1 at the same time. (Except P1/S..... see below)
Confusion seems to exist about the definition of PIC and PF. As a co-pilot you can only ever log time as P2. You may annotate your logbook as PF or PNF, but it all has to go in the P2 column.
P1/S is only loggable after a satisfactory check ride as a Commander....... an example of such would be a line check, or LST/LPC/OPC, and has to be countersigned by the check pilot.