diff --git a/include/global.h b/include/global.h
index 92450646e..e87f27641 100644
--- a/include/global.h
+++ b/include/global.h
@@ -112,8 +112,10 @@
     f;                       \
 })
 
-// Branch defines:
-// Used by other branches to detect each other.
+// Branch defines: Used by other branches to detect each other.
+// Each define must be here for each of rhh's branch you have pulled.
+// e.g. If you have both the battle_engine and pokemon_expansion branch,
+//      then both BATTLE_ENGINE and POKEMON_EXPANSION must be defined here.
 #define ITEM_EXPANSION
 
 #define ROUND_BITS_TO_BYTES(numBits)(((numBits) / 8) + (((numBits) % 8) ? 1 : 0))