That's just Rule 55 except he's not reporting the train is complete but is waiting at the Home signal.The local instruction for Truro (even with the Mid Cornwall Resignalling) is that if a platformed train is held at a red signal, at the five minute point, the guard must contact the ‘Bobby’ to confirm the train is complete. It’s a legacy from absolute block days, which ended earlier this year. However, there are all sorts of local rules which could be applied to your layout (as Tim has rightly said).
The local instruction could simply be the guard confirms to the signaller that the train is ‘complete’ on arrival. Little things like this add to the story you are portraying with your layout
That's just Rule 147