A method and system for enabling a mailer to sort incoming mail pieces in accordance with changeable criteria that are important to the mailer. This invention accomplishes the foregoing by placing a unique identifier or code tying the mail piece to a data file on each business reply envelope, on or in...http://www.google.com/patents/US7756796?utm_source=gb-gplus-sharePatent US7756796 - Utilizing a unique tracking identifier for sorting mail
