Gambling note

• California tax refund, perhaps
• Lendee's note
• Letters from a debtor?
• Short promise?
• Gambler's promise, abbr
• Promissory note, of a sort
• Letters acknowledging debt
• Letters from a short person?

Wikipedia Word definitions in Wikipedia
An IOU (abbreviated from the phrase "I owe you") is usually an informal document acknowledging debt . An IOU differs from a promissory note in that an IOU is not a negotiable instrument and does not specify repayment terms such as the time of repayment. ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
I O U \I O U\, IOU \I.O.U\([imac]" [=o]" [=u]"). [phonetic, from I owe you.] A paper having on it these letters, with a sum named, and duly signed; -- in use in England as an acknowledgment of a debt, and taken as evidence thereof, but not amounting to ...