One does get the impression that the Brits are rather pompous and precious. They keep wanting to improve R/T unilaterally, and all this does is cause arguments and some confusion: eg. whether to say "degrees" after 5 or not!
There will always be some pilots who mishear things and the key is to make the calls unambiguous and for the ATCO to check the readback - not to change CAP 413 and add the odd word here or there in an instruction, like some sort of code, when most of us are flying outside UK airspace anyway, and things are done differently there.
If Scotland produced its own CAP 413 and included some words that did not appear in the English CAP 413, wouldn't we deem it all a bit silly and insist on just one way of stating something? If so, why should the British think they can impose their own ideas unilaterally and forget about everyone else?
There shouldn't be arguments about how instructions should be worded, but they are frequent in PPRuNe. That is because there have been too many changes, and it is clear that many controllers and pilots get a bit irritated by them.
Message to the CAA: Stop tinkering with R/T procedures.
Riverboat