Ditchdigger
As I pointed out in the thread up in the R&N section, even if you're properly authorized, it's "illegal" to add "Good day",
Rubbish. CAP 413 (UK) is produced to provide guidance to UK RTF users. It states that
...Users of RTF in the UK are expected to comply with the phraseology described in this manual...
There is nothing within the manual that states use of pleasantries etc is 'illegal'. It is not standard RT Phraseology, but that's a hell of a lot different from being 'illegal'.
There are many times that even the most standard ATCO or pilot will have to use phrases/words outwith the scope of any RTF Phraseology Publication (not just CAP 413), because there are many situations that are not covered.
It is printed as a guideline and should be used
whenever possible.
However, rules governing who can speak on ATC RT etc are laid down in law.