The conditions for evidence of the use of a sub-trademark are as follows:

1. The evidence materials must have the logo of the trademark being applied for. Otherwise, the use of the applied trademark cannot be proven.

2. The evidence materials must be able to show the user of the trademark being applied for. Normally, the user of a trademark should be the registrant of the applied trademark. If the licensee uses a trademark, it is also deemed to be used by the trademark registrant, but it should clearly reflect the licensing relationship between the trademark registrant and the licensee.

3. The evidence must reflect the use of the trademark on the goods for which it has been approved.

4. The evidence must be produced within the required three consecutive years, that is, three years forward from the date of application for revocation.