An Object Identifier (OID) is used as a world wide unique identifier of objects. Others standards like GUID, UDDI exist. OID is widely recognized, mainly in the three following fields:
It is a structured number, using Abstract syntax notation 1 (ASN1), it is independent of machine-specific encoding techniques. It is defined by international ISO / ITU-T standard X.208 (1988) and X.680 (1995)
Usage
openOSI uses OID to define uniquely, on a world wide basis, it's specific objects in the three operational fields indicated above:
Certificate practice statements (Validity condition of a given class of X.509 certificate)
Definition of openOSI LDAP schema (extension of standard schema to fulfill Identity provider needs)
Contribution to Research and development in the field of biomedical GRID (UDDI repository)