Index: compat.h
===================================================================
--- compat.h	(revision 1139)
+++ compat.h	(revision 1140)
@@ -0,0 +1,39 @@
+#ifndef _COMPAT_H
+#define _COMPAT_H
+
+/*=
+Compatibility
+9100
+**/
+
+// Introduction
+/**
+We try our best to keep the maximum compatibility between each version of
+the engine. But sometimes, because of a bad design from the start, it's
+a good idea to break things (a bit). To minimize maintenance in these cases,
+we now provide compatibility flags.
+
+Current flags are:
+
+##RAYDIUM_COMPAT_ODE_OBJECT_MOVE_R1099##, to get old behavior for the
+##raydium_ode_object_move()##, function where reference element was the last
+one and not the first element of the object, as currently.
+**/
+
+__rayapi void raydium_compat_add(unsigned int flag);
+/**
+Add a new compatibility flag (or multiple ones, using the | operator) to
+the application.
+**/
+
+__rayapi void raydium_compat_remove(unsigned int flag);
+/**
+Remove a compatibility flag.
+**/
+
+__rayapi signed char raydium_compat_isset(unsigned int flag);
+/**
+Test if a compatibility flag is currently set. Mostly used by the engine itself.
+**/
+
+#endif