I can't find the actual change. I'm basing that on the fact that whilst I was at the college (1999) we were not allowed to use aircraft types (eg. "jetranger ST") but by the time I did my radar validation (a year later) we were.
Come to think of it, it could just be that I had duff instructors.
EDIT: In fact, Spitoon - you're quite correct; I've since found the right page in the book and that phraseology has been okay in the UK since 1996! Second option must be true after all.....