They are often used by genealogists for family research in pre-revolutionary Russia and the early Soviet period when vital records are missing or prove difficult to find.
[citation needed] Each directory was written exclusively in Russian Cyrillic only,[2] and contains various sections among which was an alphabetical list of residents in the city.
The following information can be found: A section immediately preceding or following that listing residents in alphabetical order was a directory of all streets, houses and flats with the names of their owners and occupants.
Publication came to a halt after the edition of 1936, coinciding with the time of Joseph Stalin's great purges and Moscow Trials.
[citation needed] Because numerous residents emigrated from Moscow after the Russian Revolution of 1917 and tens of thousands more were either arrested, shot, or sent to the gulag by the Cheka and the NKVD after 1918 the section detailing residents names is especially useful in determining until when a certain person was still living in the city, and under which address.