Wikimedia Bugzilla is closed!

The syntax {{{{ns:user}}:Foo/Bar}} ought to behave the same as {{User:Foo/Bar}}
on a wiki where "{{ns:user}}" translates to "User" (i.e. it ought to include
that page). Instead, it breaks and is output directly as "{{User:Foo/Bar}}" (or
whatever the correct value of "{{ns:user}} is).

Apart from just using the local name in the template anyway, there is a
workaround for this: the built-in "canonical names" for the namespaces (which
are the English ones) can be used on any wiki. Therefore {{User:Foo/Bar}} will
include the page {{Benutzer:Foo/Bar}} on a German wiki, and so on. 

For that reason, and because other variables, such as {{SITENAME}}, seem to work
OK, I'm going to call this 'minor severity' and 'low priority'.

[+keyword "parser", since this is probably only not working because of the
complexity of making something else work in the current not-a-parser]