diff -r 7ffd66591afe -r a298c6637c30 src/rules/rules.h
--- a/src/rules/rules.h	Fri Mar 28 11:45:01 2014 +0100
+++ b/src/rules/rules.h	Fri Mar 28 14:32:52 2014 +0100
@@ -37,5 +37,10 @@
 #include "queen.h"
 #include "king.h"
 
+#define VALID_MOVE_SYNTAX   0
+#define INVALID_MOVE_SYNTAX 1
+#define INVALID_POSITION    2
+#define AMBIGUOUS_MOVE      3
+
 #endif	/* RULES_H */