### Chinese: 注册证在有效期内是相应级别注册消防工程师的执业凭证，由注册消防工程师本人保管、使用。
### English: During the validity period of the registration certificate, it is the practice certificate of a registered fire engineer of the corresponding level, and it shall be kept and used by the registered fire engineer himself.
### Errors: There is no error in the English translation.

### Improved English: The registration certificate is the practicing certificate of the registered Fire Engineer of the corresponding level within the period of validity, which is kept and used by the registered Fire Engineer themselves.
