VMS Help SHOW, SYSTEM, Qualifiers, /HIGHLIGHT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /HIGHLIGHT[=keyword]

    Use with the /PAGE=SAVE and /SEARCH qualifiers to specify the
    type of highlighting you want when a search string is found. When
    a string is found, the entire line is highlighted. You can use
    the following keywords: BOLD, BLINK, REVERSE, and UNDERLINE. BOLD
    is the default highlighting.