--- level_read_uncommitted.result
+++ level_read_uncommitted.reject
@@ -1,3 +1,9 @@
+# -- WARNING ----------------------------------------------------------------
+# According to I_S.ENGINES, MRG_MYISAM does not support transactions.
+# If it is true, the test will most likely fail; you can 
+# either create an rdiff file, or add the test to disabled.def.
+# If transactions should be supported, check the data in Information Schema.
+# ---------------------------------------------------------------------------
 DROP TABLE IF EXISTS t1;
 connect  con1,localhost,root,,;
 SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
