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

I believe the answer is:

jack kerouac

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

'writer' is the definition.
I know nothing about this answer so I can't tell whether this works.

'rudely crack a joke about posh' is the wordplay.
'rudely' is an anagram indicator (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' with letters rearranged gives 'jackkeroac'.
'jackkeroac' enclosing 'u' is 'JACK KEROUAC'.

Can you help me to learn more?

I've seen this clue in The Independent.

Want a hint initially instead of a full solution? Install my app