I've seen such text on the doors to one shop:
Der Hund will draußen bleiben
I understand the meaning of the text, because from the context it was quite clear, that the dogs are banned from entering the shop, and not that they want to stay outside (taking into account, there are sausages inside, no dog would probably like to be outside).
However, that was intrigued me, is, what is the role of 'will' in that sentence? Is this a modal verb, which is in that context a synonym of 'soll'? Or it is a strange passive? Or it's just a text with humorous intentions?