Code change:
certainly as examining decrypted traffic. Because HTTPS has historically layered HTTP on top of TLS, which is <del> in turn layered on top of TCP, intermediaries do have access to unencrypted TCP-level transport information, such as retransmissions, and some carriers exploited this information in attempts to improve transport-layer performance RFC3135.  The most recent standardized version of HTTPS, HTTP/3 I-D.ietf-quic-http, uses the QUIC protocol RFC9000 as its transport layer.  QUIC relies on the TLS 1.3 initial handshake RFC8446 only for key exchange RFC9001, and encrypts almost all transport parameters itself except for a few invariant header fields.  In the QUIC short header, the only transport-level parameter which is sent "in the clear" is the Destination Connection ID RFC8999, and even in the QUIC long header, the only transport-level parameters sent "in the clear" are the Version, Destination </del> <ins> in turn layered on top of TCP, intermediaries have historically had access to unencrypted TCP-level transport information, such as retransmissions, and some carriers exploited this information in attempts to improve transport-layer performance RFC3135.  The most recent standardized version of HTTPS, HTTP/3 RFC9114, uses the QUIC protocol RFC9000 as its transport layer.  QUIC relies on the TLS 1.3 initial handshake RFC8446 only for key exchange RFC9001, and encrypts almost all transport parameters itself except for a few invariant header fields.  In the QUIC short header, the only transport-level parameter which is sent "in the clear" is the Destination Connection ID RFC8999, and even in the QUIC long header, the only transport- level parameters sent "in the clear" are the Version, Destination </ins> Connection ID, and Source Connection ID.  For these reasons, HTTP/3 is significantly more "opaque" than HTTPS with HTTP/1 or HTTP/2.

Related discussion:
text: …transport protocols Also tighten up description of the assumed protocol stack in (what is now) Section 6.1. Note that the UDP and TCP sections have been flipped in order, to improve section flow and clarity.
NAME - If you have a moment before our call on Friday to take a look at this PR, I'd appreciate it. I think it's important to to get that right, in order to address both the INTDIR and TSVART reviews.
From NAME As a bit of transport commentary, I don't find the setup of Section 6 compelling. While UDP is a transport in a technical sense, for the purpose of media, it is almost always a layer upon which the protocol doing the congestion control work runs. To that end, QUIC is just another more standardized case of this, just like SCTP over UDP. Rather than talking about "UDP's behavior" vs "TCP's behavior", I suggest talking about how applications over UDP for media behave vs applications over TCP for media behave.
NAME - I need to look at this more closely. I understand your point about UDP, but (because UDP is not a real transport layer, while TCP and QUIC are), I suspect (without looking closely yet) I'm going to be making sure that I explain this more clearly, without trying to explain the behavior(s) of applications running over TCP and QUIC. As an aside, I'm trying to make this clearer in drafts I'm targeting forwards Media Over QUIC/MOQ, so I actually DO believe you ... Please await results.
A +1 from NAME 's review (URL): Section 6. Evolution of Transport Protocols and Transport Protocol Behaviors I really wonder whether UDP vs. TCP vs. QUIC is actually the relevant distinction. What may actually matter are the transport services provided by the protocol stack (e.g., RFC 8095). I fully agree to a related comment in the INTDIR review.
After looking at this issue. I agree with both NAME and NAME that the emphasis should be on the interaction between (see new section describing this) media transport protocols and the transport services provided by underlying transport protocols. I'm moving the formerly-UDP section below the formerly-TCP section, because it's easier to describe what UDP is NOT doing after describing what TCP IS doing.