Mailing Terminology

This is a small sampling of the terms that the US Postal Service uses to describe the services, processes and items used in domestic and international mailing. If you can't find the definition you are lookign for, please proceed to the much more comprehensive Domestic Mail Manual.

aspect ratio-The dimension of a mailpiece expressed as a ratio of length divided by height (for letters and cards, length is the dimension parallel to the address as read). For example, a postcard 5-1/2 inches long by 3-1/2 inches high has an aspect ratio of 1.57. An aspect ratio between 1.3 and 2.5, inclusive, is required for automation compatibility.

barcode-A series of vertical bars and spaces that represent any numerical series, most often a correct ZIP Code for the delivery address on a mailpiece. The barcode facilitates automated processing by barcode readers and scanners. A barcode also can be used to convey information for Delivery Confirmation and Signature Confirmation services. barcode clear zone-A rectangular area in the lower right part of a letter-size mailpiece that must be kept free of printing and symbols, except for the barcode itself. This requirement allows automated processing machines to read or apply a barcode.

Bound Printed Matter (BPM)-A subclass of Package Services that consists of permanently bound sheets of which at least 90% are printed with advertising, promotional, directory, or editorial matter (or a combination of such matter). business reply mail (BRM)-A service that allows a permit holder to receive First-Class Mail and Priority Mail back from customers and pay postage only for the returned pieces. These pieces must have a specific address and format. Postage and per piece charges are collected when the mail is delivered back to the permit holder.

Coding Accuracy Support System (CASS)-A service offered to mailers, service bureaus, and software vendors that improves the accuracy of matching to delivery point codes, ZIP+4 codes, 5-digit ZIP Codes, and carrier route codes on mailpieces. CASS provides a common platform to measure the quality of address matching software and to diagnose and correct software problems.

Domestic Mail Manual (DMM) -The USPS manual that contains the basic standards governing domestic mail services, descriptions of the mail classes and services and conditions governing their uses, standards for rate eligibility and mail preparation, and all postage rates and fees. Domestic mail is classified by size, weight, content, service, and other factors.

First-Class Mail (FCM)-A class of mail that includes all matter wholly or partly in writing or typewriting, all actual and personal correspondence, all bills and statements of account, and all matter sealed or otherwise closed against inspection. Priority Mail is a subclass of First-Class Mail. Any mailable matter may be sent as First-Class Mail.

flat-size mail-A mailpiece that exceeds one of the dimensions for letter-size mail (11-1/2 inches long, 6-1/8 inches high, 1/4 inch thick) but that does not exceed the maximum dimension for the mail processing category (15 inches long, 12 inches high, 3/4 inch thick). Dimensions are different for automation rate flat-size mail. Flat-size mail may be unwrapped, sleeved, wrapped, or enveloped. indicia-Imprinted designation on mail that denotes postage payment (e.g., metered postage or permit imprint).

letter-size mail-A mail processing category of mailpieces, including cards, that do not exceed any of the dimensions for letter-size mail (that is, 11-1/2 inches long, 6-1/8 inches high, 1/4 inch thick).

National Change of Address (NCOA)-An address correction service that the USPS provides to mailers through USPS licensees. The licensees match mailing lists submitted to them on tape or disk against change-of-address information for the entire country from all Computerized Forwarding System units. If a match is made, NCOA can correct the address before it is printed on a mailpiece.

Nonmachinable surcharge-A surcharge on some First-Class Mail, Standard Mail, and Parcel Post pieces that have physical characteristics that prevent the pieces from being processed on automated equipment. Characteristics that make a piece nonmachinable include weight, rigidity, and uneven thickness.

Nonprofit rate-A preferred rate for a Periodicals publisher authorized to mail as a nonprofit organization.

Nonprofit Standard Mail-A subclass of Standard Mail that is available only to qualified organizations specified by U.S. statute.

Periodicals-A class of mail consisting of magazines, newspapers, or other publications formed of printed sheets that are issued at least four times a year at regular, specified intervals (frequency) from a known office of publication. Periodicals usually must have a legitimate list of subscribers and requesters.

Postal Numeric Encoding Technique (POSTNET)-The barcode system used on letter-size and flat-size mailpieces for encoding the delivery point information and ZIP+4 code information. presort-The process by which a mailer groups mail by ZIP Code so that it is sorted to the finest extent required by the standards for the rate claimed. Generally, presort is performed sequentially, from the lowest (finest) level to the highest level, to those destinations specified by standard and is completed at each level before the next level is prepared. Not all presort levels are applicable to all mailings.

Presorted Standard-The postage rate for Standard Mail pieces that are part of a mailing and that meet minimum volume and preparation requirements.

Standard Mail-A class of mail that weighs less than 16 ounces. It comprises the subclasses of Regular Standard Mail, Nonprofit Standard Mail, Enhanced Carrier Route Standard Mail, and Nonprofit Enhanced Carrier Route Standard Mail. These subclasses include circulars, printed matter, pamphlets, catalogs, newsletters, direct mail, and merchandise. Standard Mail may be sent at presorted rates and at automation rates.

ZIP+4 code-A nine-digit numeric code composed of two parts: (a) the initial code: the first five digits that identify the sectional center facility and delivery area associated with the address, followed by a hyphen; and (b) the four-digit expanded code: the first two additional digits designate the sector (a geographic area) and the last two digits designate the segment (a building, floor, etc.).