Format of U.S. patent number: patent application publication number or authorization number. The format of the application publication number is 4 digits year+serial number, for example: 20060 100 198, 20050 158320. The format of the authorization number consists of 1-7 digits, such as: 5575 155, 0 123456. No category code.
China patent number format: 1, China patent application number, without prefix CN, decimal places can be omitted. 2 China Patent Publication (Announcement) No.,including the CN prefix, without the last category code letter.
European patent number format: patent country code+digital number, such as WO03075629, US683 1838. If the number is less than 7 digits and 0 is added, the category code can be omitted.