It indicates a f-fight (5)

I believe the answer is:

arrow

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'it' is the definition.
The definition suggests a singular noun which matches the answer.

'a f-fight' is the wordplay.
'f-fight' becomes 'r-row' ('row' said with a stutter like 'fight' was; I've seen this in another clue).
'a'+'rrow'='ARROW'

'indicates' acts as a link.

Can you help me to learn more?

(Other definitions for arrow that I've seen before include "Missile for bowman" , "Quarrel, fired from crossbow" , "Missile with a straight thin shaft" , "Move swiftly" , "This points" .)

I've seen this clue in the Evening Standard.

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