School class cheers about layout of publication (6)
I believe the answer is:
format
'layout of publication' is the definition.
'school class cheers about' is the wordplay.
'school class' becomes 'form' (I've seen this before).
'cheers' becomes 'ta' (I've seen this in other clues).
'about' says the letters should be written in reverse.
'ta' written backwards gives 'at'.
'form'+'at'='FORMAT'
(Other definitions for format that I've seen before include "Arrangement (data)" , "Way of presentation" , "Broadsheet or tabloid, say" , "Style or arrangement of a TV programme" , "Prepare (a disk) for data" .)