Objids

Objids, short for object identifiers, are identifiers used to name objects in software systems and data standards. In many contexts the term refers to object identifiers (OIDs), a formal mechanism for naming items in a hierarchical, globally unique namespace. OIDs enable unambiguous reference to standards, algorithms, data structures, and services across organizational boundaries.

An OID is written as a sequence of integers separated by dots, representing a path through a tree of namespaces. The leftmost nodes identify broad categories, and deeper nodes individuate specific items. OIDs are typically encoded for transmission and storage using ASN.1 BER or DER, and they are registered with designated authorities to prevent collisions. The initial arcs are allocated by international standards bodies (ITU-T and ISO/IEC), with further allocations to companies, research groups, and standards committees.

Common uses include X.509 public-key certificates to name cryptographic algorithms and certificate policies, SNMP to identify MIB objects, DICOM to name data elements, and LDAP schemas to define attribute types. Beyond standards, OIDs are used in software metadata and configuration to provide stable, collision-free identifiers.

Because objids depend on a managed registry, proper governance is important to maintain global uniqueness. Misuse or unmanaged proliferation can lead to conflicts or ambiguity in data exchange. When referring to objids in code or data formats, it is often sufficient to treat them as opaque strings, while preserving their dotted numeric structure for interoperability.

See also: Globally unique identifiers, UUID, primary key, OID, ASN.1.