Library /sys$common/syshlp/ncphelp.hlb SET, MODULE, X25-ACCESS, USER user-id  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Specifies the user identification for use by the access routines
 in connecting to the multihost connector node.  Specify a string
 of  from 1 to 16 characters.  The default is that no user
 identification is used.