Customer Support Ruling
UPDATED January 2017
This CSR discusses the use of unauthorized endorsements.
The endorsement "Postmaster If There are Two or More Catalogs for the Same Family, The Return of the Duplicate Catalog is Requested" is not an approved endorsement that is recognized by the Postal Service.
Only the authorized endorsements listed in Domestic Mail Manual (DMM) 507.1.5.3 may be placed on USPS Marketing Mail pieces. Unauthorized endorsements should not be placed on mailing pieces. If such endorsements are used, postal employees are not obligated to honor them.
Anita J. Bizzotto
Headquarters, US Postal Service
Washington, DC 20260-3436