Original text:
The QUIC Transport Protocol RFC9000 provides a secure, multiplexed connection for transmitting reliable streams of application data. <del> Reliability within QUIC is performed on a per-stream basis, so some frame types are not eligible for retransmission. </del>  Some applications, particularly those that need to transmit real-time data, prefer to transmit data unreliably.  In the past, these This document defines two new DATAGRAM QUIC frame types, which carry application data without requiring retransmissions. <del> Note that DATAGRAM frames are only meant for unreliable transmissions.  Reliable transmission is already supported by QUIC via STREAM frames. </del> Discussion of this work is encouraged to happen on the QUIC IETF mailing list quic@ietf.org [3] or on the GitHub repository which contains the draft: https://github.com/quicwg/datagram [4].

Reviewer comments:
In the introduction, it says "Reliability within QUIC is performed on a per-stream basis, so some frame types are not eligible for retransmission" Is it really per-stream? Some frames are retransmitted even though they aren't associated with a stream. Really, the detection mechanism is packet-based, the retransmission decision is made on a per-frame basis, and for stream-specific frames there is the added consideration of stream state (i.e. do not resend if reset) I suggest replacing the sentence above with "Some QUIC frame types are not eligible for retransmission."
Do you have examples? It's common for an action to be attempted again, but not for the frame to be retransmitted. That's not quite right. QUIC does not retransmit stream frames, it instead looks at stream state to see what data needs to be retransmitted - there's an important conceptual difference there: let's say you had 100 bytes left in your packet and therefore sent 98 bytes of stream data and that got lost but now you have a full 1200 payload available, you shouldn't retransmit that 100 byte STREAM frame and instead create a new STREAM frame with as much data as you want to send. states:
So I agree with everything you're saying factually; this is an editorial, semantic gripe about what it means that reliability is on a per-stream basis and what it means that a frame is retransmitted. It's true that, for example, MAX_DATA frames aren't resent verbatim, but RFC 9000 addresses them in a section called "retransmission of information" due to the common-sense meaning of the term. What are you trying to communicate by saying that reliability is "on a per-stream basis"?
I agree that this sentence is confusing. Perhaps we just remove it entirely? NAME NAME thoughts?
NAME NAME made a proposal with
LGTM modulo one commentLGTM

Revised text:
The QUIC Transport Protocol RFC9000 provides a secure, multiplexed connection for transmitting reliable streams of application data.  <ins> QUIC uses various frame types to transmit data within packets, and each frame type defines whether or not the data it contains will be retransmitted.  Streams of reliable application data are sent using STREAM frames. </ins> Some applications, particularly those that need to transmit real-time data, prefer to transmit data unreliably.  In the past, these This document defines two new DATAGRAM QUIC frame types, which carry application data without requiring retransmissions.  Discussion of this work is encouraged to happen on the QUIC IETF mailing list quic@ietf.org [3] or on the GitHub repository which contains the draft: https://github.com/quicwg/datagram [4].