--- a/openttd.h	Tue Aug 22 16:22:07 2006 +0000
+++ b/openttd.h	Tue Aug 22 16:38:50 2006 +0000
@@ -49,6 +49,7 @@
 typedef uint32 CursorID;
 typedef uint16 EngineID; ///< All enginenumbers should be of this type
 typedef uint16 EngineRenewID;
+typedef uint16 SignID;
 typedef uint16 UnitID;   ///< All unitnumber stuff is of this type (or anyway, should be)
 
 typedef uint32 WindowNumber;