diff -r 0d6d44f403c5 -r f885804de706 src/newgrf_callbacks.h
--- a/src/newgrf_callbacks.h	Tue Sep 18 18:55:25 2007 +0000
+++ b/src/newgrf_callbacks.h	Tue Sep 18 20:41:59 2007 +0000
@@ -13,6 +13,9 @@
  * bit is set in the callback flags/trigger for a vehicle, house,
  * industry, etc.
  * Names are formatted as CBID_<CLASS>_<CALLBACK>
+ *
+ * @note Do not forget to add 15 bits callbacks to the switch in
+ *       newgrf_spritegroup.cpp (search for "15 bits callback").
  */
 enum CallbackID {
 	/** Set when using the callback resolve system, but not to resolve a callback. */