Hello,
in Germany you can find more and more open bookcases. These are bookcases within the public space where anyone can put or take books, free of charge, to read, bring back or keep, exchange, or whatever they like to do. The idea is somewhat related to bookcrossing. To give you an impression of what this looks like here’s a link to the german wikipedia article:
http://de.wikipedia.org/wiki/Öffentlicher_Bücherschrank
Is there a key to map this as a POI? If not, what would a native english speaker propose? amenity=public_bookcase? Or would you define it rather as a special kind of amenity=library; building=no; fee=no?
Thanks,
Philipp
EDIT: The actual translation would be public_bookcase, not open_bookcase as I wrote before.