VMS Help DSR, DSR Commands, .SUBTITLE, Defaults  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    o  If you do not enter either .SUBTITLE or .NO SUBTITLE, you get
       .NO SUBTITLE.

    o  If you enter the .SUBTITLE command without specifying subtitle
       text for it, you will get the effects of .AUTOSUBTITLE
       (provided you have not entered .NO AUTOSUBTITLE).

    o  If .AUTOSUBTITLE is in effect and if the text picked up from
       an applicable .HEADER LEVEL command is wider than the margins
       in effect when the subtitle is displayed, the subtitle is
       truncated and an ellipsis (...) is appended to the end of it.