option are recognized in build a route.
.SH ENVIRONMENT
.TP
-.B $FGROOT
+.B $FG_ROOT
Path used to locate data files.
.SH FILES
~/.fgfsrc
Per user configuration file.
.RE
.TP
-$FGROOT/system.fgfsrc
+$FG_ROOT/system.fgfsrc
.RS
System-wide configuration file in command line format.
.RE
.TP
-$FGROOT/preferences.xml
+$FG_ROOT/preferences.xml
.RS
System-wide configuration file in XML format.
.RE
.TP
-$FGROOT/keyboard.xml
+$FG_ROOT/keyboard.xml
.RS
Keyboard bindings.
.RE
.TP
-$FGROOT/Input/Joysticks/
+$FG_ROOT/Input/Joysticks/
.RS
Joystick bindings.
.RE
.TP
-$FGROOT/mice.xml
+$FG_ROOT/mice.xml
.RS
Mouse bindings.
.RE