I am the assigned Gen-ART reviewer for this draft. The General Area Review Team (Gen-ART) reviews all IETF documents being processed by the IESG for the IETF Chair. Please treat these comments just like any other last call comments. For more information, please see the FAQ at . Document: draft-ietf-httpbis-binary-message-04 Reviewer: David Schinazi Review Date: 2022-05-24 IETF LC End Date: 2022-06-03 IESG Telechat date: Not scheduled for a telechat Summary: Well written concise draft, apart from section 3 - see below. Major issues: None Minor issues: While this is an editorial comment, I'm raising it as a minor issue because it significantly hampers comprehension in my mind. I find Section 3 incredibly hard to reason about. In order to get to the actual format, the reader is forced to repeatedly jump forward and backwards using a notepad to track state. The draft seems somewhat akin to a game like Myst if you'll pardon the analogy. I believe that this could be resolved by the editors without too much work by doing the following: - keep the preface to Section 3 as-is, it does a great job of introducing the concepts - split up the "Message with Known-Length" diagram into two diagrams, one for known-length request and one for known-length response - similarly split up "Indeterminate-Length Message" diagram - reorder diagrams to avoid forward references, for example "Known-Length Field Section" should appear before "Message with Known-Length" since the latter relies on the former - define every field using a separate bullet following the style from RFC 9000. Currently the draft uses the notational conventions from RFC 9000 albeit incorrectly, for example "Known-Length Informational Response" does not appear in all "Message with Known-Length" structs but the square brackets indicating optionality are missing. While this is fundamentally an editorial issue that is theoretically the purview of the editors, such readability difficulties are worth discussing by the GEN Area Director if they agree with this assessment. Nits/editorial comments: None