Missing necessary information, invalid registration number. Trademark registration numbers usually consist of specific formats and structures, including specific numbers, letters or symbols. When filling in the trademark registration number, there is a lack of necessary information, or if it is not filled in in the correct format, an error will be prompted. The trademark registration number should be valid. and exists. If the registration number filled in is fictitious, non-existent or expired, the system will identify it as a format error.