Rudely crack a joke about posh writer (4,7)

I believe the answer is:

jack kerouac

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'writer' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'rudely crack a joke about posh' is the wordplay.
'rudely' indicates an anagram (rude can mean rough or unrefined).
'about' indicates putting letters inside.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'crack'+'a'+'joke'='crackajoke'
'crackajoke' is an anagram of 'jackkeroac'.
'jackkeroac' enclosing 'u' is 'JACK KEROUAC'.

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I've seen this clue in The Independent.

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