Use the xfRegister function call to associate a specific UUID with a file transfer application. The xfRegister function call can accomplish one or more of these tasks:
Only one application can be associated with a particular UUID, but any file transfer application can register more than one UUID. The last application to register as the default application or with a particular UUID becomes the current default file transfer application or the application associated with the particular UUID, respectively.
Usually, an application is registered when it is installed on a system. Alternatively, a specific application can be registered each time it is run.