The Apartment Entrance

I am staying in a one bedroom apartment overlooking the Lva Tolstovo Plaza, where there is an entrance to one of the main Metro stations. The apartment is entered through a nondescript and rather imposing iron door at 23A. The apartment is on the fourth floor of this building (the numbering starting on the second floor above ground). I have noticed that there is the Latin lettered word "Notar" cast in bold letters in the transom of the doorway, and, indeed, there is a Notary (I think this is some legal-related function--I'll have to look it up when I have a minute) on the second floor. I am interested, however, as to why the name appears at street level in Latin rather than Cyrillic characters. I have no answer, unless the Latin characters conveyed some special prestige or cachet to an esoteric function, much like the way Norman-French was used by lawyers in England.

Inside the iron door (accessed with a special pass code, which probably hasn't been changed for years) is a rather spartan landing, with staircases and galleries spiraling overhead for five stories.