[mailmaint] Paul Wouters' Discuss on draft-ietf-mailmaint-messageflag-mailboxattribute-11: (with DISCUSS and COMMENT)

[Paul Wouters via Datatracker <[e-mail]>]

Paul Wouters has entered the following ballot position for
draft-ietf-mailmaint-messageflag-mailboxattribute-11: Discuss

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DISCUSS:
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While most of my questions are comments, I find one issue raises to a DISCUSS
level:

for $istrusted:

        It SHOULD NOT be used for messages that have only passed standard
        authentication mechanisms like SPF, DKIM, or DMARC.

I feel this should really be a MUST NOT. Why is this set at SHOULD NOT level?
What would be an acceptable exception for using $istrusted?


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COMMENT:
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        Servers MAY clear these flag color keywords when a client clears the
        \Flagged system flag.

Why is this a MAY and not a SHOULD ?

        The $hasattachment and $hasnoattachment keywords are mutually
        exclusive. A message SHOULD NOT have both keywords set simultaneously.

Why is this not a MUST NOT ?

Same for the $memo and $hasmemo keywords ?