Re: [xmpp] draft-cridland-xmpp-session-00

Dave Cridland <> Mon, 09 June 2014 16:54 UTC

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Date: Mon, 9 Jun 2014 17:54:01 +0100
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From: Dave Cridland <>
To: Curtis King <>
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Cc: XMPP Working Group <>
Subject: Re: [xmpp] draft-cridland-xmpp-session-00
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On 9 June 2014 17:36, Curtis King <> wrote:

> Instead of adding an redundant flag into the XMPP spec. Why doesn’t this
> draft state the <optional/> flag explicit and give the session as an
> example? Otherwise we will be adding <optional/> to more features than
> session.

We've discussed, and rejected, this before, for example:

I'm not averse to reopening the discussion, though I'll still argue against
it. One or other of a generic <optional/> and <required/> will always be
redundant, and multiple <required/> elements will often conflict.

In any case, you'll note that <optional/> in this instance doesn't really
mean "optional" so much as "redundant" - in fact, I think the name is an
artifact of the discussion we had back then, though I can't find the thread
that proposes it in this case. (But both M-Link and Prosody do this, so I
assume it was discussed sometime).