[Tagging] Tradeoff

[Tobias]

> +1, also if they don't have something more in common I'd go this way. 

They have in common that you can put books into both.

>  The
> other place you wrote about of that allows to bring and pick-up different
> stuff could maybe also be a kind of shop?

No. Its just the same without the limitation to books.

> if there was a tradeoff for bicycles they would not have a lot in
> common with the book ones.

The idea of sharing: To be able to leave something and to pick something.

> In the university, there I've studied there was a place, there you could leave smaller things, which everyone could pick off for free. This could be a t-shirt or mp3-player or a pc-game or whatever...

This is similar to a shelf I know from a pub. There you can put
everything you like which fits into it.

> So I think it would be better to have a general tag for such a place (leave something, which you don't need any more and someone else can pick off this). If there is a limitation (eg. only books) this could be tagged additionally. 

+1

> This is quite close to the question, how to tag collection bins for charity 
> shops:
> http://wiki.openstreetmap.org/wiki/Talk:Tag:shop%3Dcharity

The difference is the size. The public bookcase are just a shelf and you
do not get in contact with money. May be the "trade" at tradeoff is
misleading. So we probably need another word.

> For places to get things for free, one could maybe use shop=* and then some 
> other tag to show it is for free. Maybe payment=free.

One problem might be the specification. Since its only for books you
could use shop=books (which would be misleading - just an example). But
for no specific stuff I do not know at value.

> amenity=reuse
> reuse:books=yes

This could be a better alternative for tradeoff. I did not find a
wiki-article. Is there one?