The .SUBTITLE command allows you to specify a subtitle for a
    running head (see .HEADERS ON). When using the default .LAYOUT
    command, the subtitle appears on the second line of every page
    (except page 1) at the leftmost position on a line (character
    position 0), regardless of the left margin setting. The .NO
    SUBTITLE command cancels the .SUBTITLE command. (See also
    .AUTOSUBTITLE, .TITLE, .FIRST TITLE, and .LAYOUT.)
    Formats
      .SUBTITLE  [text]
      .NO SUBTITLE
    Abreviated formats
      .ST  [text]
      .NST
Additional Information:
explode
extract