Etiquette for returning stolen goods fences start to consider (8)
I believe the answer is:
protocol
'etiquette' is the definition.
(protocol is a kind of etiquette)
'for returning stolen goods fences start to consider' is the wordplay.
'for' becomes 'pro' (as in being 'pro' or in favour of something).
'returning' says the letters should be written backwards.
'stolen goods' becomes 'loot' (items which have been looted).
'fences' is an insertion indicator (inserted letters are fenced off).
'start to' suggests taking the first letters.
The initial letter of 'consider' is 'c'.
'loot' enclosing 'c' is 'locot'.
'locot' in reverse letter order is 'tocol'.
'pro'+'tocol'='PROTOCOL'
(Other definitions for protocol that I've seen before include "Correct procedure" , "Formalities" , "Approved procedure" , "Good form" , "Code of conduct, etiquette" .)