The technical work of ISO is carried out through Technical Committees (TC). In total more than 180 TC's exist. [TC 22 is responsible for road vehicles].

Each Technical Committee may, in turn, establish Subcommittees (SC) and Working Groups (WG) to cover different aspects of its work.

Each Technical Committee or Subcommittee has a secretariat, assigned to an ISO member body; in case of technical committees, by the Technical Management Board, and in the case of subcommittees, by the parent TC. For each working group, a convener is appointed by the parent SC.

Within their scopes, Technical Committees and Subcommittees determine their own programmes of work, according to criteria that have been established by the Technical Management Board to identify the market requirements for individual work items.

To ensure coordination of work in all matters of common interest, liaisons are established between related Technical Committees.

Each member body interested in a subject for which a Technical Committee has been authorized has the right to be represented on that committee.

Member bodies that decide to take an active part in the work of a Technical Committee or Subcommittee are designated as P-members (Participating members) of that committee. They have an obligation to vote and, whenever possible, to attend meetings.

Member Bodies that wish only to be kept informed of the work of a Technical Committee or SC are registered as O-members (Observers).

Detailed rules for the technical work are given in the ISO/IEC Directives.

Ref. http://www.iso.org