[netmod] XML and prefix

[tom petch <[e-mail]>]

I see that IANA have taken to asking  XML Registry experts about the registration of YANG namespaces at Last Call, or perhaps they have always done this but have only recently put the e-mail on a public list.  Anyhow, the experts have taken it upon themselves to comment on the XML examples and I do not understand this comment.  This comes from  
[IANA #1217705] Expert Review for draft-ietf-i2nsf-nsf-monitoring-data-model-12 (xml-registry)
by Tim Bray 17 dec 2021 03:03

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Sorry, but this has the same problem in figure 11.1 that we've just been
discussing with Ian.

For it to work, (a) the prefix in the alarm-category element MUST be the
same as the namespace prefix for
urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring, which means that XML
software MUST be chosen that makes the namespace prefix information
available.  I don't think it's OK for the draft not to say those thigns.

<alarm-category
           xmlns:nsfmi="urn:ietf:params:xml:ns:yang:\
                      ietf-i2nsf-nsf-monitoring">
           nsfmi:memory-alarm
         </alarm-category>
=================================================
a) I am unclear what the problem is - I thought that XML allowed great freedom with prefix even if the IETF would rather not
b) this suggestion seems to be that all I-D with XML examples, which is pretty much every I-D with a YANG module in it,  needs to carry a warning about what XML software to choose, which seems  rather a burden.  Thoughts?

Tom Petch