Original text:
is expected to both expire earlier than the PTO and be less likely to spuriously retransmit data. <del> 5.3. </del>  The initial probe timeout for a new connection or new path SHOULD be set to twice the initial RTT.  Resumed connections over the same Initial packets and Handshake packets could be never acknowledged, but they are removed from bytes in flight when the Initial and <del> Handshake keys are discarded.  When Initial or Handshake keys are discarded, the PTO and loss detection timers MUST be reset, because discarding keys indicates forward progress and the loss detection timer may have been set for a now discarded packet number space. </del>  <del> 5.3.1. </del>  When a PTO timer expires, a sender MUST send at least one ack- eliciting packet in the packet number space as a probe, unless there Sending different payloads each time reduces the chances of spurious retransmission. <del> 5.3.2. </del>  Delivery or loss of packets in flight is established when an ACK frame is received that newly acknowledges one or more packets. detection proceeds as dictated by packet and time threshold mechanisms; see ack-loss-detection. <del> 5.4. </del>  A Retry packet causes a client to send another Initial packet, effectively restarting the connection process.  A Retry packet Version Negotiation packet is received.  The client MAY use this value in place of its default for the initial RTT estimate. <del> 5.5. </del>  When packet protection keys are discarded (see Section 4.10 of QUIC- TLS), all packets that were sent with those keys can no longer be

Reviewer comments:
I believe this section was mistakenly on the wrong level. I also added a reference to a later section to the last sentence. Alternatively this sentence could just be removed as this is normatively specified later on.

Revised text:
is expected to both expire earlier than the PTO and be less likely to spuriously retransmit data.  <ins> 5.2.2. </ins> The initial probe timeout for a new connection or new path SHOULD be set to twice the initial RTT.  Resumed connections over the same Initial packets and Handshake packets could be never acknowledged, but they are removed from bytes in flight when the Initial and  <ins> Handshake keys are discarded, as described below in Section discarding-packets.  When Initial or Handshake keys are discarded, the PTO and loss detection timers MUST be reset, because discarding keys indicates forward progress and the loss detection timer might have been set for a now discarded packet number space. </ins>  <ins> 5.2.3. </ins> When a PTO timer expires, a sender MUST send at least one ack- eliciting packet in the packet number space as a probe, unless there Sending different payloads each time reduces the chances of spurious retransmission.  <ins> 5.2.4. </ins> Delivery or loss of packets in flight is established when an ACK frame is received that newly acknowledges one or more packets. detection proceeds as dictated by packet and time threshold mechanisms; see ack-loss-detection.  <ins> 5.3. </ins> A Retry packet causes a client to send another Initial packet, effectively restarting the connection process.  A Retry packet Version Negotiation packet is received.  The client MAY use this value in place of its default for the initial RTT estimate.  <ins> 5.4. </ins> When packet protection keys are discarded (see Section 4.10 of QUIC- TLS), all packets that were sent with those keys can no longer be