Under FAA, the only one logging PIC during IR training in actual IMC should be the instructor
Incorrect. 14 CFR 61.51 is "aircraft rating" related only.
You're not allowed to operate PIC under IMC without the rating
Correct, but the discussion is about
logging PIC, not
operating as PIC.
Under 14 FAR 61, if you're handling the controls and rated in the category, class, and (if app.) type, you can log PIC. To be sure, it's not the "P1" type of pilot-in-command, so if you're filling out a job app for a foreign employer it almost certainly wouldn't count. It
does count for FAA ratings. I can't help with the JAR stuff, but
nh2301 and earlier posters seemed to have things right. No offense intended. The whole PIC thing makes little sense to me, but that's how it works. Have a column for each "type" of PIC and you should be well-covered. In fact, have a logbook with lots of extra (blank) columns so you can cover both sets of rules. The airplane won't fly until the weight of the paperwork ...