Turning over papers, a judge giving mark (9)
I believe the answer is:
diacritic
'mark' is the definition.
(I know that diacritic is a type of mark)
'turning over papers a judge' is the wordplay.
'turning over' shows that the letters should be reversed in order.
'papers' becomes 'ID' (identification papers).
'judge' becomes 'critic' (critic is a kind of judge).
'id' back-to-front is 'di'.
'di'+'a'+'critic'='DIACRITIC'
'giving' acts as a link.
(Other definitions for diacritic that I've seen before include "Mark" , "accent, for example" , "[ACCENT] , perhaps" , "one showing a pronounced difference" , "Capable of distinguishing" .)