Carriers’ Stamps (Carriers): The term "Carriers’ Stamps" is applied to certain stamps of the United States used to defray delivery to a post office on letters going to another post office, and for collection and delivery in the same city (local letters handled only by the carrier department). A less common usage was for a collection fee from the addressee at the post office ("drop letters"). During the period when these were in use, the ordinary postage fee defrayed the carriage of mail matter from post office to post office only.
In many of the larger cities the private (“Local”) posts delivered mail to the post office or to an addressee in the city direct for a fee of 1 or 2 cents (seldom more), and adhesive stamps were often employed to indicate payment.

Local Stamps (Locals): Stamps valid within a limited area or within a limited postal system. Local post mail requires the addition of nationally or internationally valid stamps for further service. Locals have been produced both privately and officially.