Re: [Moderator Action] [Technical Errata Reported] RFC7540 (4663)

If there were a deliberate choice to omit the "minor" version number, such needs to be stated in the RFC.  Such a choice is actually omitted, and thus I see no such intent.  What results at best is a conflict between two RFC's, and at least, an implementation error by the group which authored the HTTP/2 library I cited, which is in turn adopted by Apache, the most common HTTP server software used on the Internet (per the Netcraft survey).  I raised this as an error because I do not believe that it was the intent of this RFC to break an earlier RFC with which it claims backward compatibility in the majority of HTTP servers on the Internet.

On Tue, 4/12/16, Mark Nottingham <> wrote:

Subject: Re: [Technical Errata Reported] RFC7540 (4663)
To: "RFC Errata System" <>
Cc: "Mike Belshe" <>,, "Martin Thomson" <>,,,
Date: Tuesday, April 12, 2016, 12:31 AM

defined by the CGI specification, and the WG made a
conscious choice to omit the minor version number.

Updating the CGI specification
is more appropriate (although an errata may not be the best
way to do it for that spec either).


On 12 Apr 2016, at 5:19 PM, RFC Errata System <>
> The
following errata report has been submitted for RFC7540,
> "Hypertext Transfer Protocol Version
2 (HTTP/2)".
You may review the report below and at:
Type: Technical
> Reported by: D. Stussy
> Section: 8 omits
> Original Text
> -------------
[Note:  RFC 3875, section 4.1.16, defines the protocol
version as:
HTTP-Version = "HTTP" "/" 1*digit
"." 1*digit
> Nothing in RFC 7540 redefines this.]
> Corrected Text
> --------------
> Add
paragraph at end of section 8 (before 8.1) -
HTTP/2 preserves the format of the SERVER_PROTOCOL CGI
> both in the CGI interface and
for any server logging purposes.  Where
> a version string is necessary, it is
"HTTP/2.0" as defined by RFC 3875.
> Notes
> -----
> Compatibility
is required with a prior published RFC, or a specific change
superseding the prior RFC need be explicitly stated.  This
RFC states in its abstract:
> "This specification is an alternative
to, but does not obsolete, the HTTP/1.1 message syntax. 
HTTP's existing semantics remain unchanged"
> RFC 7540, section
3.5's connection preface string containing
"HTTP/2.0" implies that the RFC authors should
have forseen this issue, and added a paragraph to section 8
to explicitly state no change in the CGI interface variable
SERVER_PROTOCOL was desired.  At least one implementation
is using a version string of "HTTP/2", not
"HTTP/2.0", because of how it is referred in this
RFC. ("" has incorrectly implemented
this in its library routines.)
> Instructions:
> This erratum is currently
posted as "Reported". If necessary, please
> use "Reply All" to discuss
whether it should be verified or
rejected. When a decision is reached, the verifying party
> can log in to change the status
and edit the report, if necessary. 
> --------------------------------------
> RFC7540 (draft-ietf-httpbis-http2-17)
> --------------------------------------
> Title               :
Hypertext Transfer Protocol Version 2 (HTTP/2)
> Publication Date    : May 2015
> Author(s)           : M.
Belshe, R. Peon, M. Thomson, Ed.
Category            : PROPOSED STANDARD
> Source              : Hypertext
Transfer Protocol Bis APP
> Area     
          : Applications
> Stream 
            : IETF
> Verifying
Party     : IESG


Received on Thursday, 14 April 2016 20:15:52 UTC