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.