Legal analysis: generally speaking, writing an IOU for others should include the following contents: the name and address of the party concerned; The subject matter and quantity of the loan; Price or remuneration; Time limit, place and method of performance; Liability for breach of contract; Dispute settlement methods and other contents that should be included in the contract.

Legal basis: Article 470th of the Civil Code of People's Republic of China (PRC). The contents of a contract are agreed upon by the parties, and generally include the following terms: (1) the name and domicile of the parties; (2) Subject matter; (3) quantity; (4) quality; (5) Price or remuneration; (6) Time limit, place and method of performance; (7) Liability for breach of contract; (8) Methods for resolving disputes.

The parties may conclude a contract by referring to the model texts of various contracts.