Interestingly enough, the German WWII Soldbuch (paybook) had the serial number of the weapon issued to the soldier*, as well as his home town, unit, service history, information on any injuries or wounds, hospital stay if any, and so forth. They were a gold mine for American intelligence during WWII. U.S. ID cards provided only name, branch or service, rank, serial number and religion.
*Often incomplete, missing the suffix letter, date, etc., but good enough for accountability purposes.
Jim