Legal analysis: It can only be said that there is no explicit law prohibiting this piece at present. As long as both parties sign the contract and agree, it will generally be effective. However, it is difficult to achieve strong results, basically relying on the trust of both sides.

Legal basis: Article 465 of the Civil Code of People's Republic of China (PRC). Contracts established according to law are protected by law. A legally established contract is legally binding only on the parties, except as otherwise provided by law.