To be honest John, haven't a clue, I can only guess its trying to keep track of all Deactivated firearms etc, AFAIK the pre 95 ones were not in a proof house register of any sort, so maybe trying to get everyone with a deac to register it or come forward etc?? The mind boggles........
I've just enquired about a Bren Gun carrier........ although its a long shot fingers crossed, if it does come to something I'm going to need a Bren and don't fancy a new EU spec one, maybe have to wait till that window opportunity is with us.......