A string UUID contains the character-array representation of a UUID. A string UUID is composed of multiple fields of hexadecimal characters. Each field has a fixed length, and fields are separated by the hyphen character. For example:
989C6E5C-2CC1-11CA-A044-08002B1BB4F5
When providing a string UUID as an input argument to a RPC run-time routine, enter the alphabetic hexadecimal characters as either uppercase or lowercase characters. However, when a run-time routine returns a string UUID, the hexadecimal characters are always lowercase.