The prohibition has to content the staff (5)
I believe the answer is:
baton
'staff' is the definition.
(I know that baton is a type of staff)
'the prohibition has to' is the wordplay.
'the prohibition' becomes 'ban' (ban is a kind of prohibition).
'has' means one lot of letters goes inside another.
'ban' placed around 'to' is 'BATON'.
'content the' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for baton that I've seen before include "Light wand" , "Piece of equipment" , "Police (or conductor's) stick" , "Policeman's truncheon" , "It's passed in a relay race" .)