In computing, object identifiers or OIDs are an identifier mechanism standardized by the International Telecommunication Union (ITU) and ISO/IEC for naming any object, concept, or "thing" with a globally unambiguous persistent name.[1]

Syntax and lexicon


An OID corresponds to a node in the "OID tree" or hierarchy, which is formally defined using the ITU's OID standard, X.660. The root of the tree contains the following three arcs:

Each node in the tree is represented by a series of integers separated by periods, corresponding to the path from the root through the series of ancestor nodes, to the node. Thus, an OID denoting Intel Corporation appears as follows,

and corresponds to the following path through the OID tree:

  • 1 ISO
  • 1.3 identified-organization (ISO/IEC 6523),
  • 1.3.6 DoD,
  • internet,
  • private,
  • IANA enterprise numbers,
  • Intel Corporation

A textual representation of the OID paths is also commonly seen; for example,


Each node in the tree is controlled by an assigning authority, which may define child nodes under the node and delegate assigning authority for the child nodes. Continuing with the example, the node numbers under root node "1" are assigned by ISO; the nodes under "1.3.6" are assigned by the US Department of Defense; the nodes under "" are assigned by IANA; the nodes under "" are assigned by Intel Corporation, and so forth.



See also



  1. ^ "Object Identifier Repository".