Industry standard organizations define barcode standards.
AIAG 
Industry volunteers from automotive OEMs, parts suppliers and technology vendors all work together at AIAG on achieving consensus on common automotive industry rules for using bar codes, and two dimensional symbols, and other Automatic Identification technologies in applications such as shipping labels and parts identification/marking.
ANSI 
The American National Standards Institute (ANSI) facilitates development of American National Standards by establishing consensus among qualified groups.
ANSI has served in its capacity as administrator and coordinator of the United States private sector voluntary standardization system for more than 90 years. Throughout its history, ANSI has maintained as its primary goal the enhancement of global competitiveness of U.S. business and the American quality of life by promoting and facilitating voluntary consensus standards and conformity assessment systems and promoting their integrity.
EAN International
EAN was started in 1974 when manufacturers and distributors of 12 European countries formed an ad-hoc council. Its brief was to examine the possibility of developing a uniform and standard numbering system for Europe, similar to the UPC system already in operation in the USA. As a result, a UPC compatible system called "European Article Numbering" was created.
The Health Industry Business Communications
The Health Industry Business Communications Council® (HIBCC®) is an industry-sponsored and supported nonprofit organization. As an ANSI-accredited organization, their primary function is to facilitate electronic communications by developing appropriate standards for information exchange among all health care trading partners.
The Japanese Standards Association
The Japanese Standards Association is the organization responsible for establishing JAN (Japanese Article Numbering system) bar code standards. The objective of JSA is “to educate the public regarding the standardization and unification of industrial standards, and thereby to contribute to the improvement of technology and the enhancement of production efficiency".
The Uniform Code Council, now known as GS1 US
The Uniform Code Council, now known as GS1 US™, administers the Universal Product Code (UPC) bar codes for the U.S. Originally developed by the request of grocers involved in the National Association of Food Chains the UPC barcode went from supermarket to worldwide acceptance in multiple aspects of trade and commerce.