The format of the trademark registration number is fixed, consisting of two letters and a string of numbers. Among them, the letter represents the Trademark Office, F represents the Trademark Office of the State Administration for Industry and Commerce, and C represents the Trademark Office of the State Intellectual Property Office. The numerical part is generated according to certain rules and usually consists of 7 digits, sometimes 8 digits.

In China, the format of a trademark registration number is "No. XXXX", where XXXX is a specific numeric number. For example, "No. 1234567" means that this is a trademark registered with the Trademark Office of the State Administration for Industry and Commerce of China, and its registration number is 1234567.

It should be noted that different countries and regions may have different trademark registration number formats and requirements. Therefore, when applying for trademark registration, the applicant needs to carefully read the regulations and requirements of the local trademark office to ensure that the trademark registration number is filled in in the correct format.

The above content is carefully compiled by Zhubajie.com. I hope it will be helpful to you.