On a train from Basel Badischer Bahnhof to Basel SBB there is an automated announcement shortly before departure:
Cross the border only with valid travel documents and without goods and foreign currency that need to be declared.
Grenzübertritt nur gestattet mit gültigen Reisedokumenten und ohne deklarationspflichtige Waren oder Devisen.
What border is it talking about, though? Both stations are in Basel, Switzerland, aren't they?