Ciao GontseM

Here you've introduced the `b_id` key to OpenStreetMap.
I think this would be better mapped to the `ref`-key, as specified in https://wiki.openstreetmap.org/wiki/Key:ref

Greetings from Switzerland,
habi

PS: I'm here because of ~60 `b_id`s showing up at http://osm.mueschelsoft.de/taginfo/newkeys.htm :)