> An address is a property of the building (or more correctly for Bulgaria

But some of my business partners use post boxes, thus the official address (the one in the trade register) is on that post box, thus independent of e.g. the main office's location.

However, the main issue remains - independent of a city an its particular cadastre rules, web crawlers should get info about shops. The shop owners want to get found and the apps want to provide users e.g. how to route to a location. It is impossible for a crawler to know in advance that Sofia has the rule that if a node is inside an OSM area having a house number, the shop always has the same number, while in Shumen it might not be the case. Or take Berlin where on some areas shops with entrance at the backside of the house gets the suffix "b" while shops with entrances to the main street get "a". Or in Tirana (I lived there) the official address is the number of the entrance of a building. So the house has e.g. number "53" but the official address of my company there is "53/1" (and as funny as it is, there is no "53/2" only a 52/3.

Should apps like OSMAnd~ learn all cadastre rules of all countries? (and in e.g. Germany even every municipality has its own numbering rules)