Search notes:

Access Object Model: Application.GUIDFromString

GUIDFromString() returns an array of bytes: 
? typeName(guidFromString("{A7CC3DA6-ABFB-E911-81A1-005056938A20}"))
Byte()
The size of this byte array is 16 (as expected): 
g =guidFromString("{A7CC3DA6-ABFB-E911-81A1-005056938A20}")
? ubound(g) - lbound(g) + 1
 16

See also

Selecting records which are identified by GUIDs.
MS-Access GUID test
The application object.

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