Checker of movement of renumbered bottles (6)

I believe the answer is:

frenum

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'checker' is the definition.
Both the answer and definition are singular nouns.
Maybe they are linked in a way I don't understand?

'movement of renumbered bottles' is the wordplay.
'bottles' indicates a hidden word (bottling is a kind of containing).
'FRENUM' can be found hidden inside 'movement of renumbered'.

'of' acts as a link.

Can you help me to learn more?

I've seen this clue in The Telegraph.

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