Glossary of Terms

Adjusted throughput

The number of mail pieces that have been processed during the job session over the length of time it takes to run the job session minus the time that the machine has been idle.


Automated Area Distribution Center (ADC)

An area distribution center that uses automation to process automation-compatible mail. There are 107 total USPS designated ADC destinations in the US.


Automated-compatible mail

Mail that meets postal specifications concerning design, size, machine readability, and characteristics so that it can be scanned and processed by automated mail processing equipment.


Automation discount

A postage reduction offered to mailers who barcode their letters and flats and meet addressing, readability, and other requirements for processing on automated equipment.


Average throughput

The number of mail pieces that have been processed during the job session over the length of time it takes to run the job session.


Barcode Reader

A component in certain mail processing equipment that reads and interprets the barcode applied to a mailpiece.


Bound Printed Matter (BPM)

A subclass of Package Services for material that weighs no more than 15 pounds and consists of permanently bound sheets, at least 90% of the sheets are printed with advertising, promotional, directory, editorial matter, or a combination of these.


Bulk Mail Center (BMC)

Highly mechanized mail processing plants that distribute parcel post, media mail, standard mail and periodicals in bulk form.



The grouping of mailable matter into mail classes and subclasses by rate categories, according to content, weight, size, and preparation standards.


Current throughput

The number of mail pieces processed over the last minute during the job expressed in pieces per hour.


Discount Mailing Service

Services that allow mail to be sent at reduced rates, including First-Class Mail, Standard Mail, Periodicals, and Package Services. Discount mailing services, also called bulk mail, and presorted mail, usually involve higher volumes of mail and require sortation and special preparation.


Discount Rates

Reduced postage rates offered to mailers in exchange for higher standards of mail preparation, sortation, and destination entry.


Delivery Point Validation (DPV)

A special database supplied by the USPS. To meet USPS requirements, an OCR must request whether a Zip+4 coded answer resides in the USPS delivery point file as a valid address. If not, the mail piece will be marked as a "DPV reject". This means that the address does not exist.


Dynamic Sort

A sorting algorithm that allows for new sort rules to be added to a sort profile while mail is being processed based on the mail that has been previously processed.


False Positive

A mail piece that contains an address that triggers a warning that someone may be using the DPV or LACSLink databases inappropriately. When a false positive mail piece is encountered, a False Positive Report will need to be submitted to the USPS.


First-Class Mail (FCM)

A mailing service used for mail that contains personal information about the addressee. Mail must conform to First-Class rules of being under 13oz. in weight and under ¾" in thickness.



A mail piece that exceeds at least one of the maximum dimensions for letter-sized mail (11 ½" long, 6 1/8" high, and ¼" thick) but does not exceed the maximum dimensions for for flats (15" long, 12" high, and ¾" thick). A flat may be unwrapped, sleeved, wrapped, or enveloped.



Imprinted designation on mail that denotes postage payment.



A database supplied by the USPS that provides the ability to transform a Rural Route address to a standardized one.



The ability of a mailpiece to be sorted by standard mail processing equipment.


Mail Service

Class of mail (Express Mail, First-Class Mail, Standard Mail, Periodicals, and Package Services). The classification of domestic mail is based mainly on content (such as personal correspondence versus printed advertising).


Mail Service Provider

A private vendor that provides a wide range of mailing services such as printing, address quality and standardization, sorting, transporting, and entering mail for a client.


Network Distribution Center (NDC)

Will consolidate the processing of originating mail into fewer sites to achieve greater operational efficiency and reduce transportation costs while expanding the surface transportation reach for more products.



Mail that cannot be sorted on standard mail processing equipment because of size, shape, content, or address legibility. Such mail is normally processed manually and could be subject to a surcharge.



Pieces that qualify for a smaller discount because they received a 5-digit barcode instead of an 11-digit barcode.


Presorted First-Class

A nonautomation rate category for mailing that consists of at least 500 addressed mailpieces and is sorted and prepared according to Postal Service standards.


Section Center Facility (SCF)

A processing and distribution center for post offices in a designated geographical area.


Single-Piece mail

Mail sent using retail rates.


Standard Mail

A mailing service (class of mail) that comprises the subclasses of Regular Standard Mail, Nonprofit Standard Mail, Enhanced Carrier Route Standard Mail, and Nonprofit Enhanced Carrier Route Standard Mail. Circulars, printed matter, pamphlets, catalogs, newsletters, direct mail, and merchandise can be sent as Standard Mail.


ZIP Code

The system of 5-digit numeric codes that identifies the individual Post Office or delivery station associated with an address.


ZIP+4 Code

The nine-digit numeric code that identifies the individual delivery station, sector, and segment assigned with an address.

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