Key legal question
Whether the cantonal court could reject the appeal because it was filed in German rather than French.
Extracted holding
No. Under the bilateral social security convention, documents could be submitted in German, one of Switzerland's official languages, and the court could not reject them for that reason.
Extracted reasoning
Article 20bis of the convention bars authorities from refusing submissions drafted in one of the official languages of Switzerland. That rule prevails over canton-language requirements. It does not, however, oblige the court to correspond or decide in the litigant's preferred language.