Opening piece put up with identification (4,3)
I believe the answer is:
name tag
'opening' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'piece put up with identification' is the wordplay.
'piece' becomes 'gat' (both can mean a gun).
'put up' says the letters should be written backwards.
'with' is a charade indicator (letters next to each other).
'identification' becomes 'name' (I've seen this before).
'gat' in reverse letter order is 'tag'.
'tag' after 'name' is 'NAME TAG'.
Can you help me to learn more?
(Other definitions for name tag that I've seen before include "verifies one's identity" , "Form of ID" , "Identifying badge" , "One identifying" , "Personal identification" .)