Thanks Stan, I might have guessed it would be a JAA thing. I note now that JAR FCL 1.125 talks about 'qualification' and not 'rating'.
The issue is compounded by many flight schools still referring to it as a night rating when it isn't if you are a JAA PPL holder, and there not being a JAA night qualification application form (unless recently amended).
I realise now that I have a night qualification, although the application to CAA was made on a night rating form
Looks like I'll be doing 15 hours IMC