1.19.13, Go 1.20.8, and Go 1.21.1.

Go 1.22 made it an error for a request or response read by a net/http
client or server to have an empty Content-Length header.
This behavior is controlled by the `httplaxcontentlength` setting.

Go 1.22 changed the behavior of ServeMux to accept extended
patterns and unescape both patterns and request paths by segment.
This behavior can be controlled by the

At a minimum, that file should contain either a full sentence or a TODO,
ideally referring to a person with the responsibility to complete the note.

Use the following forms in your markdown:

	[http.Request]                     # symbol documentation; auto-linked as in Go doc strings
	[#12345](/issue/12345)             # GitHub issues
	[CL 6789](/cl/6789)                # Gerrit changelists

## For the release team