Rules what an officer may do under canvas? (3,12)
I believe the answer is:
ten commandments
'do under canvas?' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'rules what an officer' is the wordplay.
I cannot really understand how this works, but
'an' could be 'a' and 'a' is found in the answer.
'officer' could be 'nco' (abbreviation for non-commissioned officer) and 'nco' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'may' acts as a link.
Can you help me to learn more?
(Another definition for ten commandments that I've seen is " Orders from on high".)