The UN World Forum for the Harmonization of Vehicle Regulations develops common procedures and requirements for motor vehicle safety and environmental performance under three international agreements.

The 1998 Global Agreement enables WP.29 to establish common standards for use by nations regardless of the legal national frameworks. These standards are known as UN Global Technical Regulations (GTR). Definitions of vehicle categories and other terms used across these GTR are found in Special Resolution No. 1 (SR1).

The 1958 Agreement enables WP.29 to establish common procedures and requirements for use under type approval frameworks, including within an international system for the mutual recognition of approvals granted by national authorities. These regulations are known as UN Regulations (formerly UNECE Regulations). Nations determine which of these UN Regulations they wish to apply under their national legislation. Nations may or may not issue approvals and nations may opt out of the system for the recognition of approvals granted by other nations. Vehicle categories and other terms used across these UN Regulations are found in the Consolidated Resolution on the Construction of Vehicles (RE3).

The 1997 Agreement enables WP.29 to establish common procedures and requirements for periodical technical inspections of motor vehicles in use. These regulations are known as UN Rules.

WP.29 also maintains common instruments relevant to regulations established under these agreements. These instruments are known as Mutual Resolutions.