class of mail service, also known as fourth class, offered by the U.S. Postal Service for mailing merchandise or printed matter weighing more than 16 ounces. The contents are subject to postal inspection. The weight limit is 70 pounds per package; length plus girth cannot exceed 108 inches. Special rules and rates apply to certain items.
class, usually mailed in a carton. Parcel Post mail may be a single parcel or a large volume of bulk parcels. It is the class of mail used by catalog companies to ship merchandise to customers. There are a variety of rates and discounts based on the parcel weight, distance traveled from entry point to destination, and quantity of parcels, as well as various presort and addressing standards. Smaller parcels may instead be mailed at First-Class or Standard (A) rates. Although at one time alternative delivery companies, such as United Parcel Service, controlled 80% of the parcel delivery market, rate increases and strikes have lured many business mailers back to the USPS for at least some of their parcel shipments. Mailers have grown fearful of depending too heavily on a single supplier.
