Established regimental flag? (8)

I believe the answer is:

standard

I believe this clue is a double definition.

'established' is the first definition.
(thesaurus)

'regimental flag?' is the second definition.

(Other definitions for standard that I've seen before include "Flying colours" , "Basic criterion" , "'Reference point, touchstone (8)'" , "Flag - accepted level" , "Ordinary Level?" .)

I've seen this clue in The Times.

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