Hi!

Inn, ogrn and kpp is codes, given to any firm when registering it within government register of firms.

Due to historic and buerocratical reasons there are combination of three codes, not single one, as you may expect. Specifically, OGRN is the code in unite governmental register, as stated above, and INN is tax registration. KPP is tax registration, also - usable if firm have several branches in different districts.

Those codes may be quite useful sometimes. They actually was useful for me personally several times (though I never get them from the map), that's why I'm trying to put them for places like shops. And, by law, they are presented on shop's signs, so I beleive there is something rational in putting them to map.