added a warning about 16MB limit
diff --git a/BUGS b/BUGS
index 3e8145c..d35cff7 100644
--- a/BUGS
+++ b/BUGS
@@ -28,4 +28,9 @@
length, and encode its substructure member using indefinite length. The BER
decoder is perfectly capable of decoding such sequences.
+6. Encoding or decoding of structures with combined length greater than 16MB
+is not tested. There are some size determination bugs lurking in the produced
+code, which may cause integer overflow in certain edge cases. This restriction
+should not cause a problem in the real world, as higher level protocol typically
+have similar or tighter restrictions on the supported PDU size.