Legal analysis: Regarding the format of IOUs, we should pay special attention to the following points: 1. The format should be standardized and clear. It is suggested to use the standard format of written evidence such as IOUs and receipts. A complete IOU mainly includes four elements: creditor, debtor, debt content and return time, and of course, signature and time. The receipt should include five elements: payer, consignee, reason for delivery, delivery content and delivery time. These contents are reflected in the formal written evidence (available in shops), which is clear at a glance and the rights and obligations of both parties are very clear.

2. Matters needing attention in the form. When writing written evidence, there should be no blank lines between the lines, otherwise it is easy for the holder to add other contents. Don't write with a faded pen. It is best to use black ink or blue-black ink for pens, and black ink is also acceptable. If you write notes with ballpoint pens or other easily faded ink, the handwriting will become blurred if it is not properly preserved, which may also create opportunities for people with ulterior motives to use chemical substances to alter them.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 667 A loan contract is a contract in which the borrower borrows money from the lender, repays the loan at maturity and pays interest.

Article 668 A loan contract shall be in written form, unless otherwise agreed between natural persons. The contents of a loan contract generally include terms such as loan type, currency, purpose, amount, interest rate, term and repayment method.

Article 669 When concluding a loan contract, the borrower shall, at the request of the lender, provide the true information about the business activities and financial status related to the loan.