Add note about trans_table_19.

diff --git a/src/content_mapnode.cpp b/src/content_mapnode.cpp
index e18112ae4c7c8b7c0ff38321f7ea66974e645f87..51f2f97368e1d8da31ce77f324e7826e24878218 100644 (file)
--- a/src/content_mapnode.cpp
+++ b/src/content_mapnode.cpp
@@ -36,6 +36,11 @@ void setStoneLikeDiggingProperties(DiggingPropertiesList &list, float toughness)
 void setDirtLikeDiggingProperties(DiggingPropertiesList &list, float toughness);
 void setWoodLikeDiggingProperties(DiggingPropertiesList &list, float toughness);
 
+/*
+       A conversion table for backwards compatibility.
+       Maps <=v19 content types to current ones.
+       Should never be touched.
+*/
 content_t trans_table_19[21][2] = {
        {CONTENT_GRASS, 1},
        {CONTENT_TREE, 4},