I think that's awfully sad! - But, to the original
question, can someone
tell me where the language code, whether en or mul/und part would appear at
all? I don't understand what is being discussed. When I look at current
interwiki links on WD, I see they have their language code next to it -
surely the Multilingual Wikisource entries should not have "en" - is that
the question here?
It doesn't appear anywhere on the Wikidata interface (AFAIK) but it is
stored in the data and you can see it when doing a SPARQL query (like the
one I gave before, more specifically with the schema:inLanguage predicate),
probably in other tools reusing the data (through the API for instance).
Right now, (at least) 6 multilingual projects are tagged as in English:
Commons, Meta, Species, Multilingual Wikisource, Mediawiki and Wikidata.
Cdlt,
~nicolas