Strange code, strange protocol (7)
I believe the answer is:
decorum
'protocol' is the definition.
(I've seen this before)
'strange code strange' is the wordplay.
'strange' is an anagram indicator.
'strange' becomes 'rum' (synonyms).
'code' is an anagram of 'deco'.
'deco'+'rum'='DECORUM'
(Other definitions for decorum that I've seen before include "Seemliness" , "Good manners" , "Decency" , "Correctness or dignity of behaviour" , "Dignity of behaviour or proceedings" .)