This specification defines the binary identifier types used across Peios subsystems: the Globally Unique Identifier (GUID) and the Locally Unique Identifier (LUID).

This specification covers:

• GUID -- binary format, string representation, comparison semantics, and generation requirements
• LUID -- binary format, comparison semantics, and allocation model

This specification does not cover:

• Security Identifiers (SIDs) -- defined in PSD-004
• Well-known GUID or LUID values -- defined in the specifications of the subsystems that declare them
• Application-specific identifier namespaces