Barcode Glossary

Here are some common terms and phrases used to describe barcode labels. Select the first letter of the term you're looking for to jump to that section of this glossary. If the term starts with a digit or symbol, choose the " # " link.

“X” Dimension

The nominal dimension of the narrow bars and spaces in a bar code symbol.


The character set which contains letters, numbers and may contain other characters such as punctuation marks or control characters.


The American National Standards Institute is a non-governmental organization responsible for the development of voluntary industry standards.


The opening in an optical system (scanner) implemented by a physical baffle that establishes the field of view.


Automatic Storage and Retrieval System. Automated, robotic system for storing and retrieving items in a warehouse.


The character set and code described in American National Standard Code for Information Interchange, ANSI X3.4-1977. Each ASCII character is encoded with 7-bits (8 bits including parity check). The ASCII character set is used for information interchange between data processing systems, communication systems, and associated equipment. The ASCII set consists of both control and printing characters.

ASCII or Serial Wedge

An ASCII or serial wedge is an RS-232 scanner that is connected between the ASCII terminal and a host controller. This connection is used when keyboard wedge transmission is too slow, or when the interface is not supported by the product.

ASCII or Serial Wedge

An ASCII or serial wedge is an RS-232 scanner that is connected between the ASCII terminal and a host controller. This connection is used when keyboard wedge transmission is too slow, or when the interface is not supported by the product.


Advance Ship Notice. An EDI transaction sent ahead of the shipment listing its contents and shipping information.

Aspect Ratio

In a bar code symbol, the ratio of bar height to symbol length.


The ability of bar code reading equipment to recognize and correctly decode more than one symbology.


The liner is scored to facilitate its removal. The location is not critical. It is normally done in the center of the part when not otherwise specified. 

Bar code

An automatic identification technology which encodes information into an array of varying width parallel rectangle bars and spaces.

Bar Code Character

A single group of bars and spaces that represent an individual number, letter, punctuation mark, or other symbol.

Bar Code Density

The number of data characters which can be represented in a linear unit of measure. bar code density is often expressed in characters per inch (CPI).

Bar Code Pen ((bar code scanner))

Lowest cost and most durable, these stainless steel pens come in a variety of apertures and light sensitivities so they can be used in almost any application. Must be in contact with the bar code to read.

Bar Code Slot ((bar code scanner))

Also known as a badge reader, this input device is used to scan ID badges.

Batch Picking

Warehousing process in which goods are selected by pickers in quantities to satisfy the demand for more than one order. Goods are first picked by SKU, and later sorted by order or delivery address.


A bar code symbol capable of being read successfully independent of scanning direction.


Bill of Lading transport or Document used to acknowledge receipt of goods; may also be used to serve as a contract for the cargo.

Butt cut

 Parts are “kiss cut” on a liner but have no space (waste) between the parts. This term is normally used when describing a rotary die. The artwork should be designed to not have any graphics bleed off the edge of the label.


The external commercial entity responsible for transporting a shipment. Carriers may specialize in small packages, LTL (less-than-truckload), full truckloads (TL), rail, air, or sea.

CCD Scanner

A nice compromise in price and performance between a pen and a laser, this Charged Coupled Device (CCD) scans up to 200 times per second and reads from as far as 4 inches from the bar code. Very durable.


1) A single group of bars and spaces which represent an individual number, letter, punctuation mark, or other symbol. 2) A graphic shape representing a letter, numeral, or symbol. 3) A letter, digit, or other symbol that is used as part of the organization, control, or representation of data.

Check Character

A character included within a message whose value is used for the purpose of performing a mathematical check to ensure the accuracy of that message.


This shape is self explanatory.

Codabar ((2 of 7 Code, Code 27))

A numbers only bar code consisting of seven modules, two of which are wide. See ANSI/AIM X5-3 USS-Codabar for specifications.

Code 128

A full alphanumeric bar code capable of encoding all 128 ASCII characters. See ANSI/AIM X5-4 USS128 for specifications.

Code 39 ((3 of 9 Code))

A full alphanumeric bar code consisting of nine modules, three of which are wide. See ANSI/AIM X5-2 USS-39 for specifications.

Code 93

A full alphanumeric bar code capable of encoding all 128 ASCII characters. See ANSI/AIM X5-5 USS93 for specifications.

Continuous Code

A bar code symbology where all spaces within the symbol are parts of characters, e.g. USS I 2/5. There is no intercharacter gap in a continuous code.

Cross Docking

An efficient distribution approach in which merchandise is pre-packed by the store and moved directly from the receiving dock to the shipping dock. Eliminates the need to place inventory in storage.


Continuous Replenishment Programs. Placing suppliers in charge of replenishing retailer's inventories of supplier's goods, usually yielding lower inventory investments and higher turns.

Cutting Method

The method that is used to cut the parts.

Cycle Counts

A way of physically counting/verifying inventory levels in sections of a store or DC, usually more efficiently than other methods.


Distribution Center.

Dead Front

Applies to overlays only. Used to describe an LED type window or copy that only appears to the user when back lit. When this area is not back lit it is indistinguishable from the background color or “dead”. 

Depth of Field

The distance between the maximum and minimum plane in which a code reader is capable of reading symbols.

Die cut

 Parts are cut into individual pieces using a steel rule die to achieve the final shape.

Direct Connect

The term direct connect actually has two meanings. To some, direct connect refers to decoded output, or the ability of the scanner to read a bar code and output data directly to the host without an external decoder. Direct connect has also been used to describe a decoded output scanner connecting to a PC or host without a keyboard.

Direct thermal

This method is done in rolls and normally has a maximum O.D. of 8 inches depending on the printer used. It is similar to thermal transfer but does not require a ribbon, instead, It uses material (paper) that is chemically treated to change color (black) when heat is applied by the print head. This method should only be used for labels with a short life span due to it’s tendency to turn black when exposed to sun light.

Discrete Code

A bar code symbology where the spaces between characters (intercharacter gap) are not part of the code, e.g. USS-39.

Distribution Requirements Planning

Determining the inventory level needed in warehouses to meet anticipated customer demand over time. It is used for inventory management and as a feed for MRP.

Dot Matrix

A system of printing where individual dots are printed in matrix (5x7, 7x9, etc.) forming bars, alphanumeric characters, and simple graphics. See AIM document T11, "Matrix Impact Printing", for specifications.

Dual Interface

The ability of the scanner to connect directly to either of two different host devices and to automatically configure itself to communicate with each host. For example, a hand-held CCD may be attached to an IBM POS (Point of Sale) terminal during the day, and a portable data terminal for maintaining inventory at night. A built-in dual interface makes it easy to move a scanner between applications.


European Article Numbering System, the international standard bar code for retail food packages.


Electronic Article Surveillance.


A method of printing that utilizes a special electrostatic paper or a charged drum, both of which attract toner to the charged area. See AIM document T-12, "Electrostatic Printing".

Face score

Normally a two step cutting method. Sheets of labels are first “kiss cut” in one direction, then guillotine cut in the other creating “strips” of parts. This process cannot hold normal tolerances associated with steel rule dies due to its two stage method. Parts requiring tolerances of +/- .02 or less should not use this method.


Labels supplied with perforations at regular increments that are folded at a specific repeat (12 inches is the most common).

Film Master

A photographic film representation of a specific bar code or OCR symbol from which a printing plate is produced.

First Read Rate

See "Read Rate".

Fixed Beam Scanner

Either a visible light or laser scanner reading in a fixed plane. Requires a more exact positioning of bar code than with a moving beam scanner.

Flash Memory

A memory chip that holds its content without power. The term was coined by Toshiba for the chip's ability to be erased "in a flash". Flash memory is used by Welch Allyn in most products as an alternative to PROMs (Programmable Read Only Memory) because flash memory can be easily updated. Flash capability allows cloning, PC Menuing and full firmware updates.


The final configuration in which the parts will be shipped.

Guard Bars

The bars which are at both ends and center of a U.P.C. and EAN symbol. They provide reference points for scanning.


Parts are cut into individual pieces with equipment that uses a large blade to cut the final shape of the parts. Similar to “sheared” but multiple sheets are cut with greater speeds and accuracy due to the automated nature of the equipment.

Hand marking

The customer intends to use a pen or other writing utensil to write on the face of the label. Matte finishes work best in these situations reducing the tendency for the ink to smear. Samples should be provided for the customer to test to ensure their marking method is compatible with the material.

HHLC ((Hand Held Laser Compatible))

"Dumb" or undecoded lasers have a unique way of communicating with an external decoder. This protocol, also known as laser emulation, is used by devices such as CCD's or decoded output lasers to communicate with external decoders.

Horizontal Bar Code

A bar code or symbol presented in such a manner that its overall length dimension is parallel to the horizon. The bars are presented in an array, which look like a picket fence.

Impact printer

As the word “impact “ implies, this printing method uses pressure to transfer the pigment on a ribbon to the substrate i.e. dot matrix, typewriter etc. Although this was the method of choice a few years ago it is being replaced by a thermal transfer process due to its increased flexibility in materials and printing options.

Impact Printing

Any printing system where a micro processor controlled hammer impacts against a ribbon and a substrate.


The method that is used to print data on the label surface.

Individual pieces

A single part(s).

Ink Jet

A method of printing using liquid ink, projected a drop at a time against a substrate.

Intercharacter Gap

The space between two adjacent bar code characters in a discrete code. For example, the space between two characters in USS-39.

Interleaved Bar Code

A bar code in which characters are paired together using bars to represent the first character and spaces to represent the second, e.g., USSI 2/5 (see also "Continuous Code").

Interleaved Two of Five Code ((I 2/5))

A number-only bar code symbology consisting of five bars, two of which are wide. In this code both the bars and spaces carry information. See ANSI/AIM X51 USS I 2/5 for specifications.

Kiss cut

 A method of cutting through the face stock of pressure sensitive material but not cut through the liner.

Label Shape

All labels have a shape that falls into one of six categories.

Laser cut

 Equipment using laser technology. Normally used for first articles and prototypes. This method can be used for small production quantities (with prior approval).

Laser Scanner

An optical bar code reading device using a low energy laser light beam as its source of illumination. Often hand held.


Logistics of marking and reading symbols. A Department of Defense program to place a Code 39 symbol on all federal items. For specifications see MilStd 1189.

Magnetic Stripe Reader ((scanner))

Magnetic Stripe Readers scan credit cards and debit cards with magnetic strips. Available in combinations of one to three tracks and with or without heavy mounting bases, the Magnetic Stripe Readers are not only versatile and robust, but proven performers.


Magnetic Ink Character Recognition. The stylized printing on the lower left of personal and bank checks.


Military Standard.


A condition, which occurs when the data output of a reader does not agree with the data encoded in the bar code symbol.

Moving Beam Scanner

A scanning device where scanning motion is achieved by mechanically moving the light beam through the bars.


A unit of measure used to define the wavelength of light. Many standards require scanning in the B633-B900 range.

No cutting

The label the customer is buying does not have a specific shape. Example: A continuous roll of material not die cut in any way.

No orientation

This option would be selected when no orientation applies.

No shape

This designation is used when the label the customer is buying does not have a specific shape. Example: A continuous roll of material not die cut in any way.


The exact (or ideal) intended value for a specified parameter. Tolerances are specified as positive and negative deviations from this value.


An abbreviation commonly applied to the character set contained in ANSI Std. X3.17-1981 (ISO 1073 Part 1). The code is both human and machine readable.


An abbreviation commonly applied to the character set contained in ANSI Std. X3.49-1975. (ISO 1073 Part ll).


On-Line Transaction Processing. A class of systems that efficiently handle immediately acquired active data, such as production data, orders being processed, etc.

Order Lead Time

Time from a receipt of an order for a product through picking and delivery to a customer.


This term applies to roll label formats and is used to describe the direction of the label copy as it comes off the roll. The orientation of the die and the way the artwork is created determines this direction. 


 This shape is self explanatory.

Parcel Manifest System

Automated shipping system.

Passive Tag

Passive tags are radio frequency identification devices that do not have any internal power source. Their energy source is the power emitted from adjacent antennas.

Pattern Adhesive

In the case of screen printed products, a double linered adhesive is die cut to a specific shape that “mates” with an overlay or nameplate design. This normally applies to screen printed products. It is most commonly used when the customer needs LED windows that are adhesive free. Roll products can also need a pattern adhesive but the requirement is achieved differently. Special tooling, unique waste weeding techniques and adhesive deadeners are some of the methods used to achieve this type of specification. 


Print Contrast Signal. A measurement of the ratio of the reflectiveness between the bars and spaces of a symbol, commonly expressed as a percent. PCS is calculated as:
PCS = R1 - Rd divided by R1, where R1 is the reflectance of the light background and Rd is the reflectiveness of the dark bars.

Pen Scanner

A pen like device either connected by wire to a device or self-contained, used to read bar codes. Requires direct contact with the symbol.


Cutting rule with a series of teeth or “ties” per inch that die cut the material but keep the part intact. The strength of the perforation depends on the number and size of the teeth per inch. The customers application should determine the strength of the perforation. The purpose is to allow the end user to separate or break apart the label design as they use the parts. 


This is a generic term. The format is determined based on the number of labels across and down specified by the person entering the part for the first time. See definitions below.


In distribution, the movement of received goods to a storage area.  It can involve intermediate staging.

Quiet Zone

A clear space, containing no machine readable marks, which precedes the start character of a bar code symbol and follows the stop characters. Sometimes called the "Clear Area".

Radio Frequency Tag

An electronic tag capable of receiving/storing and/or transmitting digital information by means of, and in response to, RF energy.

Random-Location Storage

In warehouses, a storage technique in which received material is put away in any available space rather than a specific decided logical criteria.

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