Right limits to timber usage (4)

I believe the answer is:

true

'right' is the definition.
('true' is associated in meaning with 'right')

I don't understand how the remainder of the clue works.

(Other definitions for true that I've seen before include "Agreeing with fact or reality" , "Exact; faithful" , "not showing 12 [DISHONESTY]" , "Right; genuine" , "Genuine, actual" .)

I've seen this clue in The Independent.

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