One with a standard commission? (4,7)

I believe the answer is:

flag officer

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'commission?' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.

'one with a standard' is the wordplay.
'one' becomes 'officer' (I am not sure about this - if you are sure you should believe this answer much more).
'with' means one lot of letters go next to another.
'a standard' becomes 'flag' (I've seen this in another clue).
'officer' after 'flag' is 'FLAG-OFFICER'.

Can you help me to learn more?

I've seen this clue in The Irish Independent.

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