--- man.1	(revision 320400)
+++ man.1	(working copy)
@@ -328,6 +328,8 @@ 
 option.
 .It Ev MANWIDTH
 If set to a numeric value, used as the width manpages should be displayed.
+If set to a negative numeric value, and output is to a terminal,
+the width is the whole width of the screen minus the specified value.
 Otherwise, if set to a special value
 .Dq Li tty ,
 and output is to a terminal,
--- man.sh	(revision 320400)
+++ man.sh	(working copy)
@@ -637,6 +637,15 @@ 
 			use_width=$MANWIDTH
 		fi
 		;;
+	-[0-9]*)
+		if { sizes=$($STTY size 0>&3 2>/dev/null); } 3>&1; then
+			set -- $sizes
+			if [ $2 -gt 80 ]; then
+				MANWIDTH="${MANWIDTH#-}"
+				use_width=$(($2-$MANWIDTH))
+			fi
+		fi
+		;;
 	[Tt][Tt][Yy])
 		if { sizes=$($STTY size 0>&3 2>/dev/null); } 3>&1; then
 			set -- $sizes