blueskis
'VFR on top' has always been legal in UK airspace, its just that unrated PPLs can't fly out of sight of the surface because their licences don't allow it.
The point about the UK stance is that in UK airspace, being at or below 3000' clear of cloud and in sight of the surface complies with VFR it isn't mandatory as in ICAO, provided the other part of Rule 26(b) can be complied with. E.g Flying at 3000' with visibility > 5km no cloud above, below is an unbroken layer of stratus tops 1500'
Take your and bookworms point about the AIP, I am concerned when I see a sentence saying 'recommended xxxxxx, but'