Glossary of Terms

Advance deposit account
Mailer account maintained by the postal service from which postage is deducted at the time of mailing.

Area distribution center (ADC)
A designated geographical area defined by zip codes. The area distribution center is used for presort and makeup of certain classes of mails, computation of certain postal charges, distribution, and dispatch. (SCF for Missouri state mailings is Springfield, MO 65801.)

Automation compatible letter
Letter-size mail that weighs less than 2.5 ounces (3.0 ounces if the piece is pre-barcoded) and meets other physical criteria. In addition, the piece must be part of a mailing that is 85 percent zip+4 coded or delivery point barcoded.

Barcode
A series of vertical bars and half bars representing the zip code printed underneath the address on a mail piece. The barcode facilitates automated processing by optical character reader equipment.

Barcode read area
The clear zone on the bottom right-hand part of an envelope which must be kept free of printing and symbols except the barcode itself to enable automatic processing machines to read the code.

Barcode sorter
A computer-controlled, high-speed machine that sorts letters, based upon an imprinted barcode.

Carrier route presort
Mail that the mailer has arranged by carrier route. It requires no primary or secondary distribution.

Delivery point barcode
A barcode formed by adding two additional numbers (normally the last two digits of the street address) to the zip+4 barcode.

Dual address
An address with both a street address and post office box number. Delivery will be made to the address on the line immediately above city, state, and zip+4 line.

Faced
Mail arranged with all addresses and stamps or indicia upright and facing the same way.

Flat
A piece of mail that exceeds the dimensions for letter-size mail (6 1/8" x 11 1/2" or more than 1/4" thick).

Forward
To send undeliverable-as-addressed mail to a second address. Customers file form 3575, change of address order, with the local post office to have mail forwarded when they move.

Indicia
Imprinted designations on mail pieces to denote payment of postage. (these pieces must be part of a bulk or mass mailing and be prepared according to USPS standards.)

Layout
Pieces of mail that are not in zip code order that are put into zip code order by manually laying them out.

Metered mail
Any class of mail with postage printed by a USPS approved meter. The privileges and conditions of stamped mail apply to metered mail.

Minimum size requirement
The smallest dimensions allowable for all mailable matter (.007 thickness).

Optical character reader
An automatic mail sorting system that locates the address written on the face of an envelope and reads the city, state, and zip code, prints a bar code, and sorts the mail.

Permit
Mail with printed indicia instead of a stamp, showing the sender has paid postage.

Presort
A form of mail preparation. The mailer groups pieces in a mailing by zip code or other USPS-recommended separation in order to bypass certain postal operations. Presort is a USPS trademark.

Sectional center facility (SCF)
A designated geographical area defined by zip codes. The sectional center facility is used for presort and makeup of certain classes of mails, computation of certain postal charges, distribution, and dispatch. (SCF for Missouri state mailings is Springfield, MO 5801.)

Zip+4 code
The nine-digit code, established in 1981, composed of:

  1. Zip code
    The first five digits identify the individual post office or Metropolitan area delivery station associated with the address.
  2. Expanded code
    The additional four digits identify:
    1. Sector
      The first two additional digits designate a geographic portion of a zone. It can also indicate a portion of a rural route, part of a box section, or official designation.
    2. Segment
      The last two additional digits designate a specific block face, apartment house, bank of boxes, firm, building, or other specific delivery locations.