I have some bottles of Hirschbraeu beer in 500ml brown bottles with swing tops like this. On the back label, along with information about the brewery and the beer, is the instruction "Leere Flasche nicht verschliessen!"
I'd like to think I understand this sentence perfectly. It means "Do not close the empty bottle", but that seems like a bizarre thing to put on the side of a beer bottle, especially one which appears designed to be resealable. In fact, I am planning to reuse the bottle with my own homebrewed beer. Is there something I am not getting here?