John C Klensin wrote:
In RFC 2821bis-01, Section 4.2.1 (Reply Code Severities and Theory), in
the description of the generic 4yz category, described the desired
action in terms of what the client "is encouraged to" do. I was
persuaded in an off-list exchange that this can reasonably be changed to
"SHOULD" and -01 reflects that change. For 5yz, there was a similar
construction that indicates that the client "is discouraged from"
repeating the request. I was less confident about changing that to
"SHOULD NOT", so the "is discouraged" text remains in -01.
Question: Should the 5yz description be changed to use "SHOULD NOT".
If not, is "SHOULD" in the 4yz description reasonable?
To summarize the comments that have been received onlist:
Wording for 4yz:
leave as "is encouraged" 0
leave as "SHOULD" 0
MAY is better wording 1
Wording for 5yz:
leave as "is discouraged" 0
SHOULD NOT is better wording 2
could be MUST NOT 1
MUST NOT is better wording 1
For 4yz, this does not show any consensus to change from SHOULD.
For 5yz, there is a trend to use SHOULD NOT instead of "is discouraged",
but the numbers are too low to really call a consensus yet.