Original text:
4.4. <del> HTTP/3 server push is similar to what is described in HTTP/2 HTTP2, but uses different mechanisms. </del>  Each server push is identified by a unique Push ID.  This Push ID is used in a single PUSH_PROMISE frame (see frame-push-promise) which 6.2.2.  A push stream is indicated by a stream type of "0x01", followed by the Push ID of the promise that it fulfills, encoded as a variable- length integer.  The remaining data on this stream consists of HTTP/3

Reviewer comments:
The transition to "Push Streams" has no preceding mention of server push. This adds a reference to the correct section of RFC7540.
If mention of server push is desired before mention of push stream, would it be simpler to move the final sentence of the paragraph to the start?
Maybe this would be better if section 4 was moved after section 6? Then the concepts would be explained before going into the framing. I'd also like to reorder/renumber all the push frame types so they're all adjacent to one another and in a sensible order. Is there a reason they're numbered as they are? If not, I'll open an issue to renumber them.
There's already an issue to reorder some of the sections, so I'm happy to consider this as part of the same discussion. As to the numbering, the primary reason is maintaining the same frame IDs for things that stayed over from HTTP/2 -- PUSHPROMISE has the same ID, CANCELPUSH has the ID that HTTP/2 used for RSTSTREAM, and DUPLICATEPUSH is brand new and so pushes into unallocated space.
Given that is in now, do you still see this as a problem?
I think the Server Push section still lacks a simple explanation of what the push does. A sentence like what I added in this PR at the beginning would help that. Currently the Server Push section goes directly into mechanics. URL "HTTP/3 server push is similar to what is described in HTTP/2 {{!HTTP2}}, but uses different mechanisms. Each server push is identified by a unique Push ID. ..." I'd add more to the first paragraph in case people don't want to read the H2 draft.
I think I'd prefer for the reference to be to 4.4 of the current draft instead, since that does point to RFC7540 and has more context as well.
Whoops -- which also doesn't have the two-sentence explanation of what push is. That's up in the intro. Let me copy that over to 4.4.
Thanks for the added text Mike, it looks great. I'm happy with this, so it's up to you to decide when this is ready to merge.

Revised text:
4.4.  <ins> Server push is an interaction mode introduced in HTTP/2 HTTP2 which permits a server to push a request-response exchange to a client in anticipation of the client making the indicated request.  This trades off network usage against a potential latency gain.  HTTP/3 server push is similar to what is described in HTTP/2 HTTP2, but uses different mechanisms. </ins> Each server push is identified by a unique Push ID.  This Push ID is used in a single PUSH_PROMISE frame (see frame-push-promise) which 6.2.2. <ins> Server push is an optional feature introduced in HTTP/2 that allows a server to initiate a response before a request has been made.  See server-push for more details. </ins> A push stream is indicated by a stream type of "0x01", followed by the Push ID of the promise that it fulfills, encoded as a variable- length integer.  The remaining data on this stream consists of HTTP/3