VMS Help SET, TERMINAL, Qualifiers, /ANSI_CRT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /ANSI_CRT (default)
       /NOANSI_CRT

    Controls whether the terminal conforms to ANSI CRT programming
    standards. Because ANSI standards are a proper subset of the DEC_
    CRT characteristics, the default for all VT100 family terminals
    is /ANSI_CRT.