UUIDtä

UUIDtä is a term used in theoretical discussions of identifiers to describe a composite form that combines a standard UUID with a short, application-defined tag. The idea is to attach lightweight semantic information to a globally unique identifier without changing the underlying uniqueness guarantees of the UUID portion. UUIDtä is not part of any formal standard; it is a conceptual construct used for explanation and design discussions.

Structure and encoding methods

A UUIDtä consists of two parts: a 128-bit UUID (as defined by RFC 4122) and a tag that conveys resource type, namespace, or version information. In textual form, the parts are commonly joined by a delimiter, for example 550e8400-e29b-41d4-a716-446655440000|user-profile-v1. Binary representations may place the 16-byte UUID first, followed by a length-prefixed tag or a fixed-length tag field, depending on the implementation.

Generation and semantics

The UUID part uses standard generation methods (random, DCE security, or namespace-based) to ensure global uniqueness. The tag is chosen by the creator to provide contextual meaning at the application layer. Importantly, the tag does not alter the UUID’s uniqueness property; it merely supplies additional metadata that can aid parsing, routing, or filtering.

Uses and limitations

UUIDtä can facilitate quick filtering in logs, routing decisions in microservices, or multi-tenant data organization. However, because it is not an officially standardized format, interoperability can be limited. Systems consuming UUIDtä must agree on the tag vocabulary and encoding to avoid misinterpretation, and some environments may prefer purely canonical UUIDs without embedded semantics.

See also

UUID, GUID, ULID, namespace-based UUID.