1 SU
 This command is used to change user privileges, UIC, and protection.
 Each invocation of this command sets the default protection to
 (S:RWED,O:RWED,G:RE,W:RE), The UIC is set to that given on the command
 line or [1,4] as a default, and all privileges are enabled.  The
 previous UIC, protection, and privileges are saved on a stack and can
 be restored with the NU command.

 Format:

        $ SU :== $disk:[directory]SU
        $ SU [uic]   (D=[1,4])

2 Parameter
 The optional parameter is the UIC to change to.  The default is [1,4].

 The format of the UIC is:

        gggggg,mmmmmm     or     [gggggg,mmmmmm]

 Leading zeros need not be given.  gggggg is the group to be useed, and
 mmmmmm is the member number.
