Enter a clue or pattern or both:
The Clue
I.O.U. (4 letter answer)
The Answer
CHIT
Tags
Notes
The answer CHIT is common and appears about once every 300 puzzles.
Related Clues
Bill
Check
Child
Iou
l.O.U.
Marker
Memo
Tab
Voucher
Debt memo
Gambler's marker
Short note
Signed voucher
Slip in a pot
Small voucher
Office memo, in England
It might go into a pot
Definition
CHIT as a noun:
1. (check, chit, tab) = the bill in a restaurant; "he asked the waiter for the check"