Luverly
Seriously now, I've asked around what people are doing and generally seems to be as I described, in my company also. Although I am operating to and licensed under CAAV VAR-FCL, they are pretty much lifted from the JAA (virtually word for word from what I can figure out) so there is little difference in practice. For those cases at least it seems that an F/O is acting as PIC under a method of supervision acceptable to the authorities concerned. There maybe other scenarios, but within the context of this thread as far as I am concerned, my sectors as PF will be logged as PICUS.
all time recorded as SPIC or PICUS must be countersigned by the aircraft commander/flight instructor in the Remarks (column 12).
As mentioned previously, it maybe the case that the authority will accept a letter of hours verification from the company in lieu of the signatures.