Acknowledge receipt of rings, possibly (4,3)

I believe the answer is:

sign for

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'acknowledge receipt' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'of rings possibly' is the wordplay.
'possibly' indicates an anagram.
'of'+'rings'='ofrings'
'ofrings' anagrammed gives 'SIGN FOR'.

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I've seen this clue in the Evening Standard.

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