If you need to fill in the contact information, you usually fill in the mobile phone number. If you are a minor, you can usually leave your parents' mobile phone number.

Sometimes, in order to facilitate contact and avoid being unable to find someone to delay work or something important, you can fill in your spare mobile phone number, or the mobile phone number of your parents or lover, which is safer than the price.

In addition, personal contact information also includes e-mail, micro-signal, etc. These contact information generally do not need to be filled in, and there will be corresponding tips if they need to be filled in.