28 Mar
2026
28 Mar
'26
5:57 p.m.
On Sat, 28 Mar 2026, 15:20 Dave Cridland, <dave(a)cridland.net> wrote:
Right, though "backwards compatible"
in this instance has a particular
> meaning (in my opinion):
> The absence of the additional attribute or
element will result in
> behaviour conformant to the new document.
> More generally, you need a namespace bump
if one party that's acting in
> full conformance to the earliest document version using this namespace
> would no longer be conformant to the latest document using the same
> namespace - but that's ignoring any XML Schema, and given we don't require
> those for Experimental that seems fair. (XEP-0001 section 9.1 note it is
> required for Stable).
> FWIW, I don't think this definition can
be applied to the changes in
> XEP-0377, based on a very quick skim of the document and this thread.
It's exactly what has happened with XEP-0377. The new text says (quoted
verbatim):
"Servers MUST NOT process a report if the report that do not explicitly
include the corresponding processing option."
All existing implementations do not send nor check for the processing
options, they are not aware of and cannot comply with this new requirement.
As a server, I can't tell if the client doesn't support the new options or
whether it explicitly didn't include them. As a server, I can't rely on the
server honouring their absence and I have no way to detect this. This is a
breaking change every way you look at it.
Regards,
Matthew