39 CFR 501.1 - Definitions.
(a)Postage Evidencing Systems regulated by part 501 produce evidence of prepayment of postage by any method other than postage stamps and permit imprints. A Postage Evidencing System is a device or system of components that a customer uses to generate and print evidence that postage required for mailing has been paid. Postage Evidencing Systems print indicia, such as meter imprints or information-based indicia to indicate postage payment. They include but are not limited to postage meters and PC Postage systems.
(b) A postage meter is a Postal Service-approved Postage Evidencing System that uses a device to account for postage purchased and printed. The term meter as used in this part refers to a postage meter.
(c)PC Postage products are Postal Service-approved Postage Evidencing Systems that use a personal computer as an integral part of the system. PC Postage products may use the Internet to download postage to a mailer's computer from which the postage indicia may then be printed.
(f) A distributor of postage meters may be a manufacturer who leases postage meters directly to end-user customers or may be an independent entity who leases postage meters to end-user customers on behalf of the manufacturer.
(g) A customer is a person or entity authorized by the Postal Service to use a Postage Evidencing System as an end user in accordance with Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), including 604 Postage Payment Methods and Refunds, 4.0 Postage Meters and PC Postage Products (Postage Evidencing Systems).