Protest British Army discharge (5)

I believe the answer is:

demob

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

'army discharge' is the definition.
'demob' can be an answer for 'discharge' (I've seen this before). I'm not certain of the 'army' bit.

'protest british' is the wordplay.
'protest' becomes 'demo' (demonstration).
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'demo'+'b'='DEMOB'

Can you help me to learn more?

(Other definitions for demob that I've seen before include "Release from army" , "disbandment" , "send off troops" , "soldier's release" , "Discharge from military service" .)

I've seen this clue in The Sun.

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