Binary Format

A GUID is a 128-bit (16-byte) value with the following binary layout:

Offset	Size	Field	Type
0	4	Data1	uint32, little-endian
4	2	Data2	uint16, little-endian
6	2	Data3	uint16, little-endian
8	8	Data4	uint8[8]

The total size of a GUID MUST be exactly 16 bytes with no padding.

Data1, Data2, and Data3 MUST be stored in little-endian byte order.

Data4 is a raw byte array with no endianness interpretation.

ⓘ Informative

This is the mixed-endian layout inherited from DCE RPC and MS-DTYP. The first three fields follow the platform's native byte order (little-endian on x86), while Data4 is a byte sequence with no integer interpretation.

§2.1.1 Nil GUID

The nil GUID is the GUID with all 16 bytes set to zero.

The nil GUID is a valid GUID value. Specifications that require a non-nil GUID MUST state this requirement explicitly.

The nil GUID MUST NOT be produced by the generation algorithm defined in §2.4.

§2.1.1 Nil GUID #

§2.1.1 Nil GUID