The authors discuss the studies of building comparative tables of related IPC codes aтd SRSTI subject headings in respect of Section A “Human Necessities” (satisfaction of human vital needs). The IPС Section A comprises the following subsections: “Agriculture” “Foods; Tobacco”, “Personal and household effects”, “Health; Life Saving Service; Entertainment”. Considering the subject scope of these subsections, the subject headings of SRSTI sections “Engineering and applied sciences. Economic sectors”, “Intersectoral problems” were predominantly used for comparison. In IPC–SRSTI comparison, the expert evaluation of the subject scope of the corresponding rubrication vertices of the deepest hierarchical levels was carried out. Based on the lexical, conceptual and terminological analysis of the classification objects, with consideration to the structure and scope of concepts of specific solutions and corresponding subject divisions in sci-tech information systematization, the conjugated IPC codes and SRSTI subject headings and their semantic match types were identified. Based on the study findings, the comparative tables of conjugated IPC Section A codes and SRSTI subject headings were built. Totally, 9,864 IPC codes were classified in SRSTI subject headings with 25,857 semantic matches set between them.