Propriety, etiquette (7)
I believe the answer is:
decorum
This clue is a double definition.
'propriety' is the first definition.
(I know that decorum is a type of propriety)
'etiquette' is the second definition.
(I've seen this before)
(Other definitions for decorum that I've seen before include "Decency" , "good grace" , "Seemly behaviour" , "Propriety in manners and conduct" , "This is becoming" .)