Comment by orbital-decay

OSM Wiki is not the mechanically enforced schema, it's just a collection of knowledge about the actual tagging practice. Which is entirely chaotic, and the collective consensus is dynamic - usually the most used tag wins, but there are less used alternatives here and there. There are many good proposals that failed to get traction due to too few people backing them up or for some other reason.

The addresses in particular are heavily dependent on the country and region. And of course OSM is a subject for controversies and stupid edit wars as well, just like Wikipedia.

I'm not criticizing OSM, mind you - just explaining why it's hard to implement a good search in it; you have to constantly adapt your application to what people actually use in the map in different countries/language communities.