A UUID as used in AWEIS is a unique hexadecimal number that must be formatted as five groups of fixed numbers of digits. For example

• c0b41068-1c5a-11ea-80e7-2e728ce88125
• 0131f73d-ec66-47d7-9890-b8343d71ad5d
• 00000000-0000-0000-0000-000000000000

The all-zeros variant is called GUID.Empty in AWEIS documentation, based on common Microsoft and C# terminology. This is also called a nil UUID.

The following was retrieved from Wikipedia December 11, 2019.

A universally unique identifier (UUID) is a 128-bit number used to identify information in computer systems. The term globally unique identifier (GUID) is also used, typically in software created by Microsoft. When generated according to the standard methods, UUIDs are for practical purposes unique.

• Random UUID Generator
• Technical Note TN2166 Secrets of the GPT – Mac Developer Library
• How to generate and parse UUIDs (or GUIDs) in Java
• Recommendation ITU-T X.667 | ISO/IEC 9834-8 "Procedures for the operation of object identifier registration authorities: Generation of universally unique identifiers and their use in object identifiers" (freely available)
• Random UUID Probability of Duplicates
• A Brief History of the UUID