Library /sys$common/syshlp/nclhelp.hlb set, x25_access, dte_class, user (OpenVMS)  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: No user ID                   Value: Latin1String

    Default user identification to be used when connecting to the
    gateway system specified by the service nodes characteristic.
    The user id must be specified in quotes.