Last warning for one entering silly fact online (5,6)

I believe the answer is:

final notice

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'last warning' is the definition.
I know nothing about this answer so I can't judge whether this works.

'one entering silly fact online' is the wordplay.
'one' becomes 'i' (Roman numeral).
'entering' indicates putting letters inside.
'silly' indicates anagramming the letters.
'fact'+'online'='factonline'
'factonline' with letters rearranged gives 'fnalnotice'.
'i' placed within 'fnalnotice' is 'FINAL NOTICE'.

'for' acts as a link.

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I've seen this clue in the Sydney Morning Herald.

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