As you can see there is a range of theory's on the subject.
Agaricus bisporus is correct in what the spirit behind the regulations was meant to be.
In practise most pilots do it like the others have said.
To be honest if you already have the required PIC time for ATPL issue it makes not a jot of difference what you log as nobody cares about PICUS.
Once you make LHS people are only interested in PIC time so PICUS becomes a PITA when you are pulling numbers out of your log book.
Personally I got all my PIC time through instructing (all VFR with very little command descisions relating to operating a multi crew aircraft) and only logged copilot when in the RHS.
Speak to your line trainer about the way your company does it. You get Captains that really do hit the roof if they think you are logging it and others that really don't care one little bit. Most folk don't get thier log books signed every trip they log it and most companys just give you a letter saying your hours are correct which the CAA accept with no issues.