diff --git a/draft-ietf-quic-transport.md b/draft-ietf-quic-transport.md
index 733261e70d..bea25165e0 100644
--- a/draft-ietf-quic-transport.md
+++ b/draft-ietf-quic-transport.md
@@ -444,7 +444,11 @@ Google QUIC Demultipexing Bit:
 Reserved:
 
 : The sixth, seventh, and eighth bits (0x7) of octet 0 are reserved for
-  experimentation.
+  experimentation.  Endpoints MUST ignore these bits on packets they receive
+  unless they are participating in an experiment that uses these bits.  An
+  endpoint not actively using these bits SHOULD set the value randomly on
+  packets they send to protect against unwanted inference about particular
+  values.
 
 Destination Connection ID: