Note to the staff (4)
I believe the answer is:
memo
'note to the staff' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for memo that I've seen before include "- Currie, Br. politician" , "In brief, a note of events" , "Written business message, in short" , "Inter-office note" , "Office note" .)