British Army acronym describing urban warfare, it stands for Fighting In Someone's House & Causing Havoc In People's Streets. It probably comes from some squaddie saying that urban warfare was fighting in someone’s house, another realised that it spelled “FISH”. The logical thing, given the British soldiers’ sense of humour would be to add “& CHIPS” and find something appropriate to match the letters. Strictly speaking that makes it a bacronym, but a remarkably appropriate one for all that.

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