Well under JAR-OPS 1, a pilot can only have 4 functions :
(i) PIC (which includes solo, SPIC, PICUS time)
(ii) Co-pilot
(iii) Dual
(iv) Flight instructor / Flight examiner
Personnally, I have never logged a single hour as PIC U/S, & I have never had my logbook signed by anybody. For example for both the CPL & the IR checkrides, I logged the flight time as PIC (since I passed, otherwise it would have been Dual). Went to Gatwick for licence issue & the CAA did not have anything to say about that.
MF