It's OK for Americans to call out these two figures (3-4)

I believe the answer is:

ten-four

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'it's ok for americans to call out these' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'two figures' is the wordplay.
'two figures' means two substitutions for 'figure'.
'figure' becomes 'ten' (ten is a number).
'figure' becomes 'four' (I've seen this before).
'ten'+'four'='TEN-FOUR'

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I've seen this clue in The Guardian.

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