"...The program is intended to round up flat tubs, letter trays & sleeves, rolling stock (including hampers & cages), pallets, and mailbags that are not in use and return them to USPS inventory. ..."
Reference: www.usps.com
Stamp Collecting | 2024 Stamp Yearbook | USPS.com - Postal Store "...Detailing every stamp issued by the U.S. Postal Service in 2...