Note to employees (4)
I believe the answer is:
memo
'note to employees' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for memo that I've seen before include "Businesslike message" , "Reminder (abbr)" , "Brief note, usually between co-workers" , "In brief, a note of events" , "- Currie, Br. politician" .)