Subject: [quicwg/base-drafts] f254fe: Clarify reserved values.

From: Mike Bishop <[email-masked]>
Date: Wed, 29 Apr 2020 13:20:20 -0700

Branch: refs/heads/master
  Home:   https://github.com/quicwg/base-drafts
  Commit: f254feb0490fb248aa0a4ccd6351072e8e9206b6
      https://github.com/quicwg/base-drafts/commit/f254feb0490fb248aa0a4ccd6351072e8e9206b6
  Author: Bence Béky <[email-masked]>
  Date:   2020-04-29 (Wed, 29 Apr 2020)

  Changed paths:
    M draft-ietf-quic-http.md

  Log Message:
  -----------
  Clarify reserved values.

Clarify reserved values for stream types, settings identifiers, frame
types, and error codes.

0x1f * N + 0x21 for the value of N = -1 is 0x02.  Literal interpretation
of the current text includes this as a reserved value.  The
parenthetical examples given in Section 11.2 make it clear that this was
not the intention, rendering this PR editorial.

The main motivation of this PR is not that the current text is
inconsistent, but that parenthetical examples from 11.2 are necessary to
correctly interpret the definitions in sections 6.2.3, 7.2.4.1, 7.2.8,
and 8.1.

Alternative wordings could be:
"0x1f * N + 0x21 for N = 0, 1, 2, ..."
"0x1f * N + 0x02 for positive integer values of N"
"0x1f * N + 0x02 for N = 1, 2, 3, ..."
"0x21, 0x21 + 0x1f, 0x21 + 2 * 0x1f, ..."
"a value of at least 0x21 with a remainder of 0x02 modulo 0x1f"
"a value of at least 0x21 that is congruent to 0x21 modulo 0x1f"
none of which is better than what this PR proposes.