[Standards] the meaning of "MUST be empty"

Kevin Smith kevin.smith at isode.com
Tue Jun 19 11:47:16 UTC 2018

On 19 Jun 2018, at 12:09, Bartłomiej Górny <bartlomiej.gorny at erlang-solutions.com> wrote:
> Hi
> If a XEP states that an attribute "MUST be empty", does it mean that it:
> a) must be present and have a value ""
> b) must not be there
> c) can be either of the two
> The question arose because of XEP-0313, which in point 5.1.2 says:
>    "When sending out the archives to a requesting client,
>    the 'to' of the forwarded stanza MUST be empty"
> and then gives an example where forwarded stanzas have no 'to' attribute. We just hit a situation where there are conflicting implementations, and we want to sort it out The Right Way, hence the question.

Sounds like we messed up the text, sorry. The right thing is to not include a to, rather than including a to=“” (which is illegal).


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