wire / identifier / uuid-nil

Nil UUID (all-zero)

The Nil UUID is the special UUID with all 128 bits set to zero: 00000000-0000-0000-0000-000000000000. RFC 9562 defines it as a sentinel meaning 'no UUID' / absent value. Its version and variant nibbles are both zero, so it does not match any real version's bit pattern.

identifier kind identifier status standard verification verified tier B identifier@1

aka: nil UUID · null UUID · zero UUID · empty GUID

identifier

spec: RFC 9562 §5.9

length 128 bits not sortable hex with dashes (8-4-4-4-12)

example:

00000000-0000-0000-0000-000000000000

fieldbitsmeaning
all_zero128Every bit is 0. Version nibble = 0 and variant nibble = 0, so it is not a valid v1-v8 value.

provenance

see also

agent: curl -H 'accept: application/json' wire.phall.io/identifier/uuid-nil or /identifier/uuid-nil.json