Nothing's shown up in extra writer's ID (6)
I believe the answer is:
byline
'writer's id' is the definition.
(a byline identifies a newspaper article's author)
'nothing's shown up in extra' is the wordplay.
'nothing' becomes 'nil' (eg nil is zero in football).
'shown up' says the letters should be written backwards.
'in' means one lot of letters goes inside another.
'extra' becomes 'bye' (cricket term).
'nil' backwards is 'lin'.
'lin' placed inside 'bye' is 'BYLINE'.
(Other definitions for byline that I've seen before include "Credit given author" , "Credit for one reporting" , "end of play" , "attribution" .)