Books confiscated by Twitter billionaire after review (8)

I believe the answer is:

libretti

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

'books' is the definition.
(libretto is a kind of book)

'confiscated by twitter billionaire after review' is the wordplay.
'LIBRETTI' is hidden back-to-front in amongst the letters.
However, I'm uncertain how this is indicated.

Can you help me to learn more?

(Other definitions for libretti that I've seen before include "score-books?" , "Opera texts" , "Da Ponte's texts" , "Words" , "Books" .)

I've seen this clue in The Telegraph.

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