Corrections sent madmen off the rails (10)

I believe the answer is:

amendments

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'corrections' is the definition.
(amendment is a kind of correction)

'sent madmen off the rails' is the wordplay.
'sent madmen' anagrams to 'AMENDMENTS'.
But, I am not sure how this is indicated.

Can you help me to learn more?

(Other definitions for amendments that I've seen before include "adjustments required" , "Changes to parliamentary bill" .)

I've seen this clue in The Independent.

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