According to Article 5 of the Guidelines for the Implementation of Investor Suitability Management in Futures Operating Institutions (Trial), when selling products or providing services to investors, operating institutions should fully understand the investor information stipulated in Article 6 of the Measures for the Administration of Investor Suitability in Securities and Futures, and can adopt but not limited to the following methods: (1) Inquiring and collecting investor information; (2) Questionnaire survey; (3) knowledge test; (4) Other on-site or off-site communication, etc.