Transfer of jailed mob due in 2012, say (7,7)

I believe the answer is:

diamond jubilee

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'2012 say' is the definition.
I can't judge whether this definition defines the answer.

'transfer of jailed mob due in' is the wordplay.
'transfer of' is an anagram indicator (I've seen 'transferring' mean this).
'jailed'+'mob'+'due'+'in'='jailedmobduein'
'jailedmobduein' with letters rearranged gives 'DIAMOND JUBILEE'.

Can you help me to learn more?

(Other definitions for diamond jubilee that I've seen before include "Celebration of Victorian age" , "for reprise in just over ten years?" .)

I've seen this clue in The Independent.

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