How marcher's flag might be confirmed? (6)

I believe the answer is:

upheld

I'm a little stuck... Click here to teach me more about this clue!

'confirmed?' is the definition.
(upholding is a kind of confirming)

I can't explain the rest of the clue.

(Other definitions for upheld that I've seen before include "Supported decision or belief" , "Sustained" , "Confirmed, supported" , "Confirmed something disputed" , "Maintained (a custom)" .)

I've seen this clue in the Sydney Morning Herald.

Want a hint initially instead of a full solution? Install my app