Prove authenticity. In the issuance of graduation certificates, students' graduation certificates must be stamped with the seals of the graduation school and the local education authorities, otherwise they will be considered by the verifier to be "made" from the school through abnormal methods to verify the authenticity. As the embodiment of the company's will, the official seal is a legal document of the company's internal management and external business activities, and its value cannot be underestimated.