IOU is a kind of documentary application written to the relevant unit or individual when an individual or unit owes money or things. White stripes are also called "IOUs" today. IOU is also a common written document in daily life to prove that one party owes money to the other, and it is an application style of credentials.

IOUs generally consist of three parts: title, text and signature, with specific contents:

(1) title. The title of IOU is generally composed of language names, that is, the word "IOU" is written in large font at the top and middle of the text. Some people write the words "temporarily owed" or "now owed" in this position as the title, but the text of this title is written in the top box of the next line.

(2) the text. The subject of the IOU should write down what the person or unit owes, what it owes and how much it owes, and indicate the repayment date.

(3) signature. Signature should be accompanied by the name of the owed unit and the personal signature of the handler, and the personal name of the owed party should be attached to the debit note issued by the individual. Meanwhile, the date of signing the debt. Units should build official seals and individuals should build private seals.