Incontrovertible evidence for correction? (6)
I believe the answer is:
proofs
'incontrovertible evidence for correction?' is the definition.
I can't judge whether this definition defines the answer.
'evidence for correction?' is the wordplay.
'evidence' becomes 'proof' (evidence proves something).
'for correction?' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'proof'+'s'='PROOFS'
Can you help me to learn more?
(Other definitions for proofs that I've seen before include "Trial impressions of printed matter - sound conclusive" , "test prints" , "What setter must check" , "negative trials" , "Trial printed pages" .)