For your information, the next deployment version of MediaWiki will have a small change in the behavior of interlanguage links.
Currently, in Wikimedia wikis, if you type:
[[de:Test]] [[de:Experiment]]
in a page, both links will be rendered. However, only one link will be stored in the database and available through the API (see bug 24502: https://bugzilla.wikimedia.org/show_bug.cgi?id=24502 ).
This changeset: https://gerrit.wikimedia.org/r/#/c/25232/
causes only one (the first) link to be rendered and stored in the database, preventing the inconsistency between database state and rendered output. This will be the new behavior with 1.21wmf2, which will be deployed starting 10/15.
Cheers, Erik