diff --git a/draft-ietf-quic-recovery.md b/draft-ietf-quic-recovery.md
index 0b2e830fcb..8e57c6a7e6 100644
--- a/draft-ietf-quic-recovery.md
+++ b/draft-ietf-quic-recovery.md
@@ -538,11 +538,14 @@ MUST ensure that the crypto retransmission timer is set if there is
 unacknowledged crypto data or if the client does not yet have 1-RTT keys.
 If the crypto retransmission timer expires before the client has 1-RTT keys,
 it is possible that the client may not have any crypto data to retransmit.
-However, the client MUST send a new packet, containing only PING or PADDING
-frames if necessary, to allow the server to continue sending data. If
-Handshake keys are available to the client, it MUST send a Handshake packet,
-and otherwise it MUST send an Initial packet in a UDP datagram of at least
-1200 bytes.
+However, the client MUST send a new packet, containing only PADDING frames if
+necessary, to allow the server to continue sending data. If Handshake keys
+are available to the client, it MUST send a Handshake packet, and otherwise
+it MUST send an Initial packet in a UDP datagram of at least 1200 bytes.
+
+Because packets only containing PADDING do not elicit an acknowledgement,
+they may never be acknowledged, but they are removed from bytes in flight
+when the client gets Handshake keys and the Initial keys are discarded.
 
 The crypto retransmission timer is not set if the time threshold
 {{time-threshold}} loss detection timer is set.  The time threshold loss