December 16, 2018 marked the 100th anniversary of the formation of the Reference Bureau within the Library of the State Rumyantsev Museum. This date is quite rightly considered the birthday of the specialized bibliographic service of the Russian State Library (RSL). Practically from the first years, the specialized bibliographic division of the Library was considered as a complex unit integrating bibliographic service and compiling activity with the considerable elements of scientific-methodical, organizational-coordinating and even scientific-research work in the field of bibliography. Despite the repeated internal restructuring and renaming of division, this approach has continued for many decades. In 1926, the Reference Bureau joined the “super complex” of Scientific-bibliographic Department, which became the basis for more specialized bibliographic divisions, created there beginning with mid-1940s. Over the following years, the bibliographic service of the RSL has undergone numerous structural transformations (mergers and demergers) and has repeatedly changed its name. Analyzing the historical experience, we can distinguish three cross-cutting directions of bibliographic activities of the Library, conventionally designated as reference-, scientific- and recommendatory-bibliographic. To the 100th anniversary the Scientific Research Department of Bibliography of the RSL prepared the Retrospective Index “Bibliographic activities of the Russian State Library (1918—2018)”, reflecting the literature on bibliographic activities of the RSL and its publications on the problems of bibliographic science and practice.