functional manuals

Group of six manuals published by the U.S. Postal Service, including the domestic mail manual (DMM) and the international mail manual (IMM) used by most mailers and the various administrative policy and procedure manuals used only by the USPS The regulations described in the DMM and the IMM are subject to some degree of interpretation. When in doubt, you should contact your Postal Service customer service representative or local postmaster, who can be very helpful in interpreting the regulations, frequently to the mailer's advantage.