Article 11 of the Contract Law stipulates: "Written form refers to contracts, letters and data messages (including telegrams, telexes, faxes, electronic data exchanges and emails) that can tangibly express the contents", that is to say, electronic data is also in written form, so employees who resign by email, WeChat, SMS, etc. submit their resignation in written form.

Article 31 of China's "Labor Law" stipulates: "A laborer shall notify the employing unit in writing 30 days in advance when canceling the labor contract". Article 37 of China's Labor Contract Law stipulates: "A laborer may terminate the labor contract by notifying the employer in writing 30 days in advance. The employee may terminate the labor contract by notifying the employer three days in advance during the probation period. " Both emphasize "written form".

Written form refers to the contract form in which the will of the parties is expressed in words and a contract is concluded. A contract and any document that records the contents of the parties' offer, acceptance and rights and obligations are concrete manifestations of the written form of the contract. The biggest advantage of written form is that the contract is well documented, and it is easy to provide evidence when disputes occur, so that it is easy to distinguish responsibilities. Therefore, for contracts with complex and important relationships, it is best to take written form. However, oral contracts recognized by both parties, oral contracts that have fulfilled their main obligations and other oral contracts recognized by law are valid.

Paragraph 2 of Article 1 16 of the Supreme People's Court's Interpretation on the Application of the Civil Procedure Law of People's Republic of China (PRC) stipulates that electronic data refers to information formed or stored in electronic media by means of e-mail, electronic data exchange, online chat records, blogs, microblogs, mobile phone short messages, electronic signatures and domain names.