Generally I think RT standards have dropped.
However, I agree with AerBabe- practice and listen!
For students, it's a good idea to look over standard calls or perhaps practice them with another student. Some (most?) flying schools have a "local" radio procedures cheat sheet for students as a supplement to CAP 413 (The R/T bible!). Or if possible visit the tower for an hour or so. Or listen out on a transceiver/receiver.
As for the A/G service...
If the call "request taxi" was made, surely the A/G controller could either give the standard "G-XX, runway 24 etc" or "G-XX, Station Radio, unable to provide taxi clearance, runway 24... etc" "G-XX, taxiing..." I'm sure that was the way I wrote the "local procedures" for a site I used to fly from Although some could still not follow them
I don't think the aircraft can call "G-XX taxiing runway..." without first calling the A/G service.
F3G- Yes "radar heading" is not CAP413 (See thread on ATC forum) and not one I use. Is it not correct in
theory, as the aircraft has been issued a heading from a radar controller?