International Organization for Standardization (ISO)

This arc is for International Standards and ISO Member Bodies.

This arc is managed by ISO and IEC but the registration authority is ANSI (American National Standards Institute). Operation is in accordance with Rec. ITU-T X.660 | ISO/IEC 9834-1 "Procedures for the Operation of OSI Registration Authorities: General Procedures and ASN.1 Object Identifier tree top arcs".

All decisions related to subsequent arcs, other than the assignment of additional secondary identifiers to top-level arc 1 (see Rec. ITU-T X.660 (2004) | ISO/IEC 9834-1:2004, A.5), will be recorded as amendments to Rec. ITU-T X.660 | ISO/IEC 9834-1 (such changes to the joint ITU-T | ISO/IEC text will be regarded as editorial by ITU-T).

From Rec. ITU-T X.660 (2004) | ISO/IEC 9834-1:2004, "the top-level arcs are restricted to three arcs numbered 0 to 2; and the arcs beneath root arcs 0 and 1 are restricted to forty arcs numbered 0 to 39. This enables optimized encodings to be used in which the values of the top two arcs for all arcs under top-level arcs 0 and 1 encode in a single octet in an object identifier encoding (see the Rec. ITU-T X.690 series | ISO/IEC 8825 multi-part Standard).