Formal notifications of commercial failings (7)

I believe the answer is:

advices

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'formal notifications' is the definition.
The answer and definition can be both related to communication as well as being plural nouns.
Maybe they are linked in a way I don't understand?

'commercial failings' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'failings' becomes 'vices' (I've seen this in another clue).
'ad'+'vices'='ADVICES'

'of' is the link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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