(Terminology in National Standard GB / T 12905-2000 of the People's Republic of China)

Bar code (bar code) A set of regularly arranged bars, spaces and their corresponding characters of the mark, used to represent certain information.
Bar code system (bar code system) A system consisting of bar code symbol design, production and scanning and reading.

Reflectivity (reflectance; reflectivity) The ratio of reflected light intensity to incident light intensity.

Diffuse reflection (deffuse reflection) The phenomenon of light reflected on a rough surface reflecting in all directions.

Specular reflection The phenomenon of light projected on a smooth surface reflecting in all directions.

Bar (dark bar; black bar) The part of the bar code with low reflectivity.

Space (light bar) The higher reflectivity part of the bar code.

The start character (start character; start cipher; start code) is located at the beginning of the bar code and is empty.

Stop character (stop character; stop cipher; start code) A number of bars and spaces at the end of the bar code.

The blank area (clear area; quiet zone; quiet area; clear zone) is a limited area where the bar code start and end symbols have the same reflectivity as the empty outside of both ends.

The bar code symbol (bar code symbol) includes the bar code in the blank area.

Character set A collection of letters, numbers, and symbols that a bar code symbol can represent.

The central seperating character (central seperating character) is located in the middle of the bar code to separate several pieces of data from the space.

Separator A special character in the coded character set that acts as a separator.

Bar code character (bar code character) means a number of characters or symbols and empty.

Bar code character set (bar code character set) A set of bar code characters that a bar code can represent.

Bar code data character (bar code data character) Bar code character that represents specific information.

Bar code check character (bar code check character) indicates the bar code character of the check code.

Bar code filler character (bar code filler character) Bar code character that does not represent specific information.

Element (element) constitutes a bar or space of bar code characters.

Bar height The height dimension of the bar perpendicular to the width of the cell.

Bar width (bar width) The width dimension of the bar in the bar code character.

Space width The space width dimension of bar code characters.

Bar width ratio (bar width ratio) The width ratio of the widest bar to the narrowest bar in the bar code.

Space width ratio The width ratio of the widest and narrowest spaces in a barcode.

X dimension
X The nominal size of the narrow unit in the bar code symbol.

Z dimension
The actual size of the narrow element in the Z bar code symbol.

Width to narrow ratio
N The sum of the width of the average wide bar and the width of the average wide space (bar code character spacing is not included) divided by twice the Z size. It is the technical parameter in the width adjustment coding method.
Calculation formula: N = (bar width of average wide bar + space width of average wide bar) / 2Z

Bar code length The length from the leading edge of the bar code start character to the trailing edge of the end code.

The length of the bar code symbol (bar code symbol length; symbol length) includes the length of the bar code that goes blank.

Aspect ratio The ratio of bar code length to bar height.

Bar code density The number of bar code characters represented by a unit length bar code. (Note: It is usually expressed in CPI, that is, the number of barcode characters that can be expressed per inch.)

Code character gap (inter-character gap) The area between adjacent bar code characters that does not represent specific information and has the same reflectivity as the empty area.

Module The basic unit of bar code characters is composed of modules and coding methods.

A bearer bar surrounds the side or frame of the barcode and has the same reflectivity as the bar.

Continuous bar code (continuos bar code) Bar code without bar code character spacing.

Discrete bar code (discrete bar code) Bar code with bar code character spacing.

Bi-directional bar code (bi-directional bar code) Both ends of the bar code symbol can be used as the starting bar code for scanning.

Add-on barcode (add-on) indicates the barcode of additional information.

Odd-even check (odd-even check) A method of checking based on the number of 0 or 1 in the binary digits being odd or even.

Self-checking bar code (bar code of the self-checking bar code).

Fixed length of bar code (fixed length of bar code) A barcode with a fixed number of barcode characters.

Unfixed length of bar code (unfixed length of bar code) Bar code with a fixed number of bar codes.

Width Encoding (width encode) The barcode encoding method in which the bar and space in the bar code symbol are composed of two types of units: wide and narrow.

Module combination encode method (module combination encode) The character of the bar code symbol is a bar code encoding method composed of a specified number of modules.

Binary-edge-code Two types of unit width barcodes, bar code characters composed of two width units.

Multi-code (four-edge-code) A variety of unit width bar codes, bar code characters composed of three or more width units.

Odd permutation (odd permutation; odd parity) module combination coding method, the sum of the number of modules contained in a bar code character is an odd arrangement.

Even permutation (even permutation; even parity) In the module group coding method, the sum of the number of modules contained in a bar code character is an even arrangement.

Bar code logic value (bar code logic value) Use binary "0" and "1" to represent the bar code character expression.