To avoid rejection by Postal Service personnel or air carriers, mailers must ensure that their packages comply with all labeling, marking, and ancillary endorsement requirements.
Hazardous, restricted, or perishable items-except for firearms (refer to 432.1(c)), switchblade knives (refer to 443.2), motor vehicle master keys (refer to 452.3), controlled substances (refer to 453.4(a)), and certain drugs eligible for mail-back programs (refer to 453.71(a))-must be clearly marked and labeled on the address side of the mailpiece (refer to 325.1 and DMM 102.1.1 and 202.1.1). Other markings required by the Postal Service or other federal regulatory agencies also must appear on the address side of any mailpiece containing hazardous, restricted, or perishable matter as specified in 325.1. These markings must be made with an insoluble material or other material that cannot be rubbed off or smeared.
Only in limited situations where sufficient space does not exist, DOT markings may be placed on a side adjacent to the address. Markings and labels must not be placed on the bottom of a package or envelope.
Except for diagnostic specimen mailpieces using Business Reply Mail format and nonregulated materials, all packaging containing hazardous, restricted, or perishable items must include a domestic return address with the sender‘s name and address.
Except for certain restricted matter specified in Chapter 4 (refer to reference list in 221.1), the contents must be clearly identified on the address side to ensure the item is mailable. A mailability determination may be required based on the mailer‘s disclosure concerning the contents at the time of mailing.
Mailers may use an endorsement to request forwarding, return, or address-correction services for undeliverable items (refer to 325.2 and DMM 507.1.5).
All packages, including those containing hazardous, restricted, or perishable items, must display an Intelligent Mail package barcode (IMpb) and an Intelligent Mail matrix barcode (IMmb). Refer to DMM 204.2.0.
