Restricted Matter

Restricted Matter - Any item on which certain mailing restrictions have been imposed for legal reasons other than risk of harm to persons or property involved in moving the mail and that require specific endorsements and markings. Examples include intoxicating liquors, abortive or contraceptive devices, odd-shaped items in envelopes, motor vehicle master keys, locksmithing devices as well as odor-producing materials, certain liquids and powders, and battery-powered devices. (Compare with hazardous material.)

[Category=Postal ]

Source: USPS, 27 October 2009 09:17:36, http://www.usps.com/cpim/ftp/pubs/pub32/pub32q_z.html