Postal Definitions


Army/Air Force post office.

Aspect Ratio

The dimension of a mailpiece expressed as a ratio of height to length.


That little piece of paper on the back of an envelope that gets removed via perforation and is another opportunity to get your advertising message seen. Commonly seen on credit card envelopes that are included with your monthly invoice.


A series of vertical full bars and half bars representing ZIP Code information relative to the address on the mailpiece.

Barcode Read Area

The clear zone on the lower right corner of an envelope that must be kept free of printing and symbols except for the barcode itself.

Barcode Sorter (BCS)

A computer-controlled machine that sorts letters, based on an imprinted barcode on the letters, at speeds of 32,000 pieces an hour.

Basis Weight

The weight in pounds of a ream (500 sheets) of paper cut to a specific standard size for that grade.

BMC (bulk mail center)

A highly mechanized mail processing plant that distributes Standard Mail and Periodicals.


Business Reply Card


Business Reply Envelope

Break-Even Point

The minimum number of sales a Direct Mail campaign must generate in order for the direct marketer to recover associated costs of the campaign.


A single sheet of paper inserted in a Direct Mail piece that's usually used to deliver another offer within the package.


The process of separating continuous forms.

Business Reply Mail (BRM)

Specially printed cards, envelopes, cartons and labels that may be mailed without prepayment of postage. The postage and fees are collected when the mail is delivered back to the sender. This service enables mailers to receive First-Class Mail, without postage, back from customers by paying the postage and fees on receipt of the mailpieces.

Business Reply Mail Accounting System (BRMAS)

An automated method for sorting, counting, and rating business reply mail (BRM) for authorized mailers.

CASS (Coding Accuracy Support System)

A certification verifying the accuracy of the address information in a mailing.

Cheshire - Label

These types of labels look like normal white computer paper but a special machine, called the Cheshire machine can cut this paper into label sized strips (usually 3 5/16" x 1") and glue them onto mailing pieces.

Cleaned List

One that is free of duplication and unwanted names/addresses.


To put together a number of inserts or pieces of paper for a purpose. Such as collating 10 pages together, so as you can staple them.


The mail package format/creative that's done the best for you; the one that's yielded the greatest response.

Courtesy Reply Mail (CRM)

A preprinted return envelope or card provided as a courtesy to consumers. Customers responding to the original mailing pay the return postage.

Data Entry

Entering names and addresses into a computer one at a time from printed or hand written material.


Can be as simple as a card file; a collection of information stored in a computer medium that can be easily accessed and manipulated.

DBMC (destination bulk mail center) rate

A discounted rate the Postal Service offers for mail that is properly prepared and entered at the BMC that serves the delivery address on the mail.

DDU (destination delivery unit) rate

A discounted rate the Postal Service offers for mail that is properly prepared and entered at the delivery unit that serves the delivery address on the mail.

Delivery Barcode Sorter (DBCS)

A small, multilevel, high-speed barcode sorter that finalizes letter mail sortation to the carrier sector/segment level using a two-pass operation to sort up to 34,000 pieces an hour.

Delivery Point Barcode (DPBC)

A ZIP+4 barcode containing two additional digits (represented by 10 additional bars) that designate a specific delivery point.


Those characteristics that define a particular group of people, including HHI, age, education level, family size, etc.

Domestic Mail Manual (DMM)

The Postal Service manual containing most regulations for domestic mail services.

DPBC (delivery point barcode)

A POSTNET bar-code that consists of 62 bars denoting the 9-digit zip code and the first 2-digits of the primary street address.

DSCF (destination sectional center facility) rate

A discounted rate the Postal Service offers for mail that is properly prepared and entered at the SCF that serves the delivery address on the mail.

Em Height

A unit of measure exactly as high as the point size of the type being set. In 12-point type, the em height is 12 points high.

Em Space

A unit of measure exactly as wide as the point size of the type being set. In 12-point type, the em space is 12 points wide.

Facing Identification Mark (FIM)

A pattern of vertical bars printed in the upper right portion of the mailpiece just to the left of the indicia, used to identify business reply mail and certain other bar-coded mail. The FIM is an orientation mark for automated facing and canceling equipment.


The collection of all letters, numbers, punctuation marks, etc. within a certain size and style.


Fleet post office (Navy & Marine Corps).

Fulfillment House

A company specializing in responding to and tracking orders sold through Direct Mail.

Gate Fold

A type of fold where both sides of a piece get folded inward so the edges come together.


The reproduction of continuous-tone artwork, such as a photograph, though a crossline or contract screen, which converts the image into dots of various sizes for printing.


Household income.


Any item, such as a brochure or pamphlet, that is placed in a Direct Mail package.

International Mail Manual (IMM)

The Postal Service manual containing most regulations for international mail services.

Jiffy Bag

Generally a corrugated, padded or bubble bag often used to mail an article that needs protection, such as a cassette or video tape.

Johnson Box

The top part of the letter, set above the body of the letter, that states the main message of the offer in a compelling way; the letter's "headline."


Reducing space between characters. Negative letter spacing.

Laser Clear - Labels

See Laser labels, except these are translucent in appearance.

Laser White - Labels

Laser labels are also known as pressure sensitive sheet fed labels. Basically, the labels peel off a backing and stick onto another surface, and each sheet of labels is independent of each other.


The arrangement of text blocks, headlines and graphics on a page.

Letter Fold Writing In

Piece is folded inwards from both sides in such a way so that they overlap each other. When completed the writing of the front page is folded facing inwards.

Letter Fold Writing Out

Piece is folded inwards from both sides in such a way so that they overlap each other. When completed the writing of the front page is folded facing outwards.


A company that personalizes, labels, sorts and stuffs envelopes in preparation for Standard Mail A®.

Lift note

A folded sheet that is a "last chance" to deliver an advertising message. Usually written by a person other than the main writer of the letter. Good place for a testimonial.

List broker

An individual or company that brings together owners of lists and the Direct Mailers who use them.

List compiler

An individual or company that specializes in gathering names, addresses and information from a variety of sources to produce a customized list of prospective customers.

Live stamp/live postage

A "normal" stamp which a consumer would use, as opposed to metered mailings.

Mail processing barcode sorter (MPBCS)

A machine that sorts between 32,000 and 37,000 letter mailpieces an hour according to barcodes previously applied to the mailpieces.


The process of keeping together a unique insert to the addressee that goes with at least one other unique insert in the same package, or a unique insert to the addressee that goes with the address information located on the outside of the package. For example a personalized letter that needs to be matched with the address displayed on the outside of the envelope.


A term for a camera-ready paste-up of artwork. It includes type, photos, line art, etc., all on one piece of artboard.


The process of combining two or more lists into a single one using the same sequential order, then sorting them together, usually by ZIP Code®.


The process of combining more than one data file and deleting out the duplicate entries.


A unit of measure equal to 0.001 inch.

Multiline optical character reader (MLOCR)

A machine that scans ("reads") an entire address block on mail, translates the address into a corresponding barcode, sprays the barcode onto the mail, then sorts the mail to an appropriate stacker with a throwout of 30,000 to 37,000 pieces an hour, depending on the type of mail.

Nanometer (nm)

A unit of wavelength (when applied to light) of 10 X-9 meters (1 billionth of a meter).


To place a piece inside a part or all of another piece.
  • To place a card with directions inside an invitation.
  • To place a reply card inside the flap of a reply envelope.
  • When a multi-page letter needs to be folded together as one, often a mailhouse will z-fold the letters individually and hand put them together. Then the entire letter can be inserted as one multi-paged document. The process of putting the letters together would be nesting.

OCR (optical character reader)

A computerized mail processing machine that scans addresses on mail and applies the proper barcode.

OE (outer envelope)

The envelope that your package will be delivered in. Usually, a "teaser" line is on the front to entice the recipient to open your letter.

Overs (or overruns)

The portion of a print run that exceeds the quantity specified in the purchase order.

PAVE (Presort Accuracy Evaluation) certification

A certification verifying that a mailing is presorted accurately to Domestic Mail Manual (DMM) standards.




A class of mail consisting of magazines, newspapers, or other publications that are issued at least four times a year at regular, specified intervals. Among other restrictions, there must be at least a 50% paid circulation and containing no more than 75% advertising in half the issues published during a 12-month period.


This is an authorization stamp issued by the post office that allows mailers to not affix postage, and instead have the post office debit from their postage account.

An example of this is:
First Class
U.S. Postage
[Company Name]

Personalized Laser Letter

A document printed from a laser printer where each page has some form of personalization such that each one is unique.


The center-to-center spacing between two adjacent objects such as characters in a line of characters, bars in a barcode, or lines in an address block.


A typographical unit of measure equal to approximately 1/72" (0.0138").

Poly Bag

A clear polyurethane bag often used to mail magazines and newsletters.

POSTNET (postal numeric encoding technique)

The barcode system for encoding the delivery point information and 9-digit zip code information on letter-size and flat-size mailpieces.

Precancelled Stamps

Stamps cancelled by printing across the face before they are sold to mailers.


A free gift sent to a potential customer either with the mail piece (front-end) or after the prospect has responded (back-end).

Prepress Proofs

Also known as "off-press proofs." these are made by photomechanical or digital means in less time and at lower cost than press


The process by which a mailer prepares mail so that is sorted down to the finest extent required by the Post Office.

Pressure Sensitive Continuous Feed - Labels

Pressure sensitive type labels, peel off a backing and stick onto another surface, such as a mail piece. Continuous feed means the label pages are attached to each other and are fed through the printer by pin holes.

Print Contrast Ratio (PCR)

The print reflectance difference divided by background reflectance and expressed as a percentage.

Print Reflectance Difference (PRD)

The background reflectance minus print reflectance and expressed as a percentage.

Proportional Spacing

The spacing of characters in a line where the space occupied by a character is proportional to the width of that character, as opposed to fixed spacing where every character occupies the same amount of space regardless of its actual width.


These are characteristics, habits, attitudes, lifestyle and behavior patterns that can help you identify your audience, or eliminate names of those who aren't.


The process of eliminating duplicates and/or unwanted names from one or more lists.


A type of fold where a piece gets folded in half, and then in half again. Both folds are in the same direction.

Remote Bar Coding System (RBCS)

A system that uses image data of handwritten mail that cannot be read by a MLOCR and incorporates automated address recognition and operator intervention to determine appropriate barcode.

Return-On-Investment (ROI)

Anticipated profits above costs incurred.

RFM (recency/frequency/monetary)

A key formula used with most databases. It lets direct marketers know the recency and frequency of purchasing, and the amount of money spent by the people in their database.

Right Angle Fold

A type of fold where a mailpiece gets folded in one direction, and then in another direction. Eg. a 17 x 11 piece getting folded in half to 8 ½ x 11 then folded in half (or in thirds), but in the opposite direction, so that the finished size is 8 ½ x 5 ½ (or 8 ½ x 3 2/3).

Roll Fold

A type of fold where one side of a piece gets folded inward and then folded inward again at least once more, like you are rolling a piece up.

Saddle Stitching

Stapling a publication from the back to the center.

SCF (sectional center facility)

A postal facility that serves as the processing and distribution center for post offices in a designated geographic area.


A mailpiece that mails without the use of an envelope. An example of this is an 8 1/2 x 11 sheet tri-folded, addressed and mailed by itself.


The short crosslines at the ends of the main strokes of letters in certain type styles.

Service Bureau

A company specializing in such computer services as mail list management and merge/purge operations.

Shelf Life

The length of time before an item (such as a catalog) becomes obsolete.


The misalignment or slant of a character, bar, line of characters, or barcode with respect to the bottom or top edge of the mailpiece.


In Direct Mail, the arrangement of pieces in a bulk mailing by ZIP Code® to facilitate processing and more reliable delivery.

Standard Mail A®

Formerly known as "Third Class" or "Bulk" mail.


The line or lines forming a character such as the stem or the top of a "T."


Using information on one or more lists to remove duplication of specific names before a mailing, or to eliminate those undesirable names.


The maintenance of records concerning various aspects of mailings, e.g., response rate, date mailed, location of respondents, etc.


A type of fold where the sides of a piece both get folded inward, usually one third of the length of the piece.


An individual or company that generates high-resolution text and graphics. The typesetter can produce the high-quality output needed to produce professional-looking printed matter.


The number of pieces by which a printing run is short of the quantity specified in the purchase order.

Web Press

A press that prints on rolls (or webs) of paper instead of single sheets.

White Space

Areas on a page that have no printing on them.

Wide Area BarcodeReader (WABCR)

A modification to the mail processing barcode sorter that permits the machine to find and "read" a barcode virtually anywhere on a mailpiece.

Window Envelopes

Envelopes having an opening through which an address printed on an insert is visible.


Piece is folded inwards once and outwards once, like in the shape of a Z.

ZIP (Zone Improvement Plan) Code

Established in 1963, the system of 5-digit codes that identifies the individual post office or metropolitan area delivery station associated with an address.

ZIP +4

A nine-digit numeric code incorporating the original five-digit ZIP Code, a hyphen, and four additional digits. The first five digits identify the delivery office. The four-digit add-on identifies a specific delivery segment such as a city block face, a floor of a building, a department from within a firm, or a group of post office boxes.

Neither nor Mailers Haven LLC nor the U.S. Postal Service is responsible for the accuracy of this information. For the most up-to-date information available, go to the U.S. Postal Service website at