A Universally Unique Identifier (UUID) is a 128-bit value that is guaranteed to be unique. UUIDs are used in the Bluetooth SDP to identify services. Some UUIDs are defined by the Bluetooth specification for specific protocols or uses.
You need to generate unique application-specific UUIDs for your application(s). A variety of different ways of generating UUIDs are possible:
Using the “uuidgen” utility of a local Linux-based computer
Using other similar tools that are also available in Microsoft Windows and other environments.
You can also generate UUIDs manually, for example as described in the Forum Nokia document Games Over Bluetooth: Recommendations To Game Developers.