Poet's old verse on papers (4)
I believe the answer is:
ovid
'poet's' is the definition.
(famous Roman poet)
'old verse on papers' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'verse' becomes 'v'.
'on' means one lot of letters go next to another.
'papers' becomes 'id' (identification papers).
'o'+'v'+'id'='OVID'
(Other definitions for ovid that I've seen before include "Latin poet (Ars amatoria, Metamorphoses)" , "Old linesman" , "Roman poet N void (anag)" , "Roman poet (Metamorphoses)" , "Roman love poet" .)