diff --git a/source/blender/makesdna/DNA_ID.h b/source/blender/makesdna/DNA_ID.h
index e3a6f50531d..f2feb8cd8e4 100644
--- a/source/blender/makesdna/DNA_ID.h
+++ b/source/blender/makesdna/DNA_ID.h
@@ -750,7 +750,11 @@ enum {
   LIB_TAG_LIB_OVERRIDE_NEED_RESYNC = 1 << 21,
 };
 
-/* Tag given ID for an update in all the dependency graphs. */
+/* Tag given ID for an update in all the dependency graphs.
+ *
+ * NOTE: when adding flags check if they should be included when passing zero to functions such as
+ * #DEG_id_tag_update. see: #deg_recalc_flags_for_legacy_zero for flags that are excluded.
+ */
 typedef enum IDRecalcFlag {
   /***************************************************************************
    * Individual update tags, this is what ID gets tagged for update with. */