@item length=@var{line-count}
-Physical length of a page, in lines. Headers and margins are subtracted
-from this value. Default: @code{66}.
+Physical length of a page. Headers and margins are subtracted from
+this value. You may specify the number of lines as a number, or for
+screen output you may specify @code{auto} to track the height of the
+terminal as it changes. Default: @code{66}.
@item width=@var{character-count}
-Physical width of a page, in characters. Margins are subtracted from
-this value. Default: @code{130}.
+Physical width of a page. Margins are subtracted from this value.
+You may specify the width as a number of characters, or for screen
+output you may specify @code{auto} to track the width of the terminal
+as it changes. Default: @code{79}.
@item top-margin=@var{top-margin-lines}