Building state infrastructure of sci-tech information in Russia requires a harmonized approach toward classification of sci-tech documents, data and scitech literature, and development of appropriate thematic profile of the vocabulary. Based on the findings of the research projects of the Russian National Public Library for Science and Technology (RNPLS&T) as the back-up organization of the Standardization Technical Committee 191 "Sci-tech information, library services, publishing, and document management", as well as on the base of the materials of emerging All-Russian Register of Sci-tech Libraries and Centers of Sci-tech Information, the author substantiates the need for standardized classification of sci-tech information and sci-tech literature for the purposes of the national scitech policy, digital transformation and federal project "Advancement of sci-tech libraries". She proposes the methodological approaches toward classification of documented sci-tech information and sci-tech data, subject classification with SSRSTI, UDC, LBC and other universal classification systems, and acquisition of a glossary as a thematic profile of the vocabulary of the State System of Sci-tech Information. Integration of the register of sci-tech libraries and sci-tech information centers with the unified classifications and terminology will build the foundation for the single information space and enable to the register for strategic planning, resources assessment, and support of sci-tech development of Russia's regions.