An IRI/URI Namespace for International Object Identifiers (OIDs)

The International Object Identifier tree provides a hierarchically based identification scheme for objects/resources, using almost all Unicode/ISO 10646 characters to identify arcs in the tree. The first identifier in the sequence can be the name of any standards body or any other organization that requests an unambiguous identification of that organization, with subsequent identifications in the hierarchy being allocated by that organization. The OID tree has been in existence since about 1984 in a numerical form, but the ability to have arcs identified by Unicode labels to identify arcs of the International Object Identifier tree was only standardized in 2008. There are just under 100,000 allocated Object Identifiers that are recorded in the OID Repository at http://www.oid-info.com This form of URI/IRI commences with "oid:/" and is followed by a series of Unicode labels separated by the SOLIDUS '/' character, identifying a node in the hierarchical International Object Identifier tree. NOTE - The SOLIDUS '/' character is not permitted in Unicode labels. An IRI can contain most of the Unicode characters, and in particular can contain all the characters allowed in a Unicode label. A URI is restricted to the ASCII character set, but [RFC3987], clause 3.1 specifies the conversion of the characters allowed in an IRI into the characters allowed in a URI, enabling both an IRI and a URI to carry the same semantics for the identification. This mapping is an integral part of the "oid" URI/IRI scheme. This enables names based on the Unicode labels in the International OID tree to be used wherever an IRI or a URI is required.

This sub-clause uses the ABNF notation commonly used in IETF RFCs (see [RFC 5234]). An IRI in the "oid" scheme is syntactically the ABNF construct "oidiri" defined as follows (with the semantics specified in 2.5), and with no white-space between lexical items: When used as a URI, the transformations specified in [RFC 3987], clause 3.1 are applied.

The "firstarcid" is required to be a Unicode label assigned to one of the arcs from the root of the International OID tree specified in [ITU-T X.660] (including long arcs) that identifies a node in the International OID tree. The next "unicodelabel" in the "subsequentarcid" is required to be a Unicode label that identifies an arc from that node to a lower level node. This repeats until the final Unicode label identifies an arc, and hence a node of the International OID tree, that is the referenced resource. NOTE - The last identified node is not necessarily a leaf of the tree, but is the identified resource.

The internationalized resource identifier is specified as an abstract sequence of Unicode characters. The encoding of those characters depends on the specification of the protocol in which they are carried, but will normally be UTF8.

This scheme can be used by any specification requiring an IRI or URI based on the international OID tree to identify an object.

Matching rules are based on exact equality of the sequence of abstract Unicode characters forming the IRI. There are no other known interoperability issues.

There are no security implications in the use of this IRI scheme.

This document is a product of the joint ISO/IEC and ITU-T ASN.1 & OID group. All members of the group are thanked for their efforts in this work.