I've looked EVERYWHERE for a proper answer to this (including the official ANO stuff
Aeronautical information is contained in the UK AIP not the ANO. Try ENR 1.1 para 3.4 Radiotelephony, Radio Failure and Loss of Communication Procedures.
Then you could try CAP413 Chapter 2 Communication Failure
You should also be familiar with the
Kirkwall data in the Aerodrome specific page of the AIP?