In addition to expressing the signer's personality, some people usually use signature files to record some documents, such as the QQ number and telephone number of good friends. Of course, you can also fully express the mood of the signer at this moment, such as "I'm in a bad mood today and want to cry" and "bonus!" , "Xilin Lu invited me to dinner" and so on, and these mood signature characters will be permanently stored in the QQ space, and can also be evaluated by friends who care about you, so as to increase the emotional interaction and communication between friends. In addition, it is usually used for commercial purposes or the guidance of company websites, such as writing "Tencent member fast track" and "virtual host domain name sale" on QQ personalized signature.