| Value | Meaning |
|---|---|
| unknown-1 | Unknown version |
| timeBased1 | Version 1 |
| dceSecurity2 | Version 2 |
| nameBasedMD53 | Version 3 (Name based + MD5) |
| randomNumberBased4 | Version 4 (Random) |
| nameBasedSHA15 | Version 5 (Name based + SHA-1) |
| timestampRandom7 | Version 7 (milliseconds since unix epoch + random) |
RFC 4122 defines different UUID versions. The version shows how a UUID was generated, e.g. a version 4 UUID was generated from a random number, a version 3 UUID from an MD5 hash of a name.
Note: All of these UUID versions can be read and processed by std.uuid, but only version 3, 4 and 5 UUIDs can be generated.