Salary ceilings (4)
I believe the answer is:
caps
'salary ceilings' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for caps that I've seen before include "Headgear for internationals" , "Bottle tops" , "Imposes limits on" , "Coverings, for heads say" , "Crowns" .)