Send an immediate ACK

draft-ietf-quic-recovery.md

@@ -228,8 +228,9 @@ an ACK immediately when receiving a second ack-eliciting packet.
 In order to accelerate loss recovery and reduce timeouts, the receiver SHOULD
 send an immediate ACK when it receives a new packet which is not one greater
 than the largest received packet number. A receiver MAY send immediate ACKs
-for the next few ack-eliciting packets that are received, but not for more
-than 1/8 RTT after receiving the out-of-order packet.
+for the next few ack-eliciting packets that are received, but SHOULD not
+send an immediate ACK for more than 1/8 RTT after receiving an out-of-order
+packet.
 
 Similarly, packets marked with the ECN Congestion Experienced (CE) codepoint in
 the IP header SHOULD be acknowledged immediately, to reduce the peer's response