To update the SRSTI – UDC conversion tables, in the context of the SRSTI master version effective since 2026, the studies were conducted for: semantic relations between new SRSTI headings and UDC codes; refinement of interreflection of UDC codes and existent SRSTI headings in case of name changes in the latter; adjustment of semantic relations of SRSTI heading associated thematically with excluded headings and UDC codes. Based on the study findings, 1,425 changes to the SRSTI – UDC conversion table were made; in particular 1,147 semantic matches were identified between the new SRSTI headings and UDC codes (26.07% – equivalent relations, 44.29% – hierarchical subordination, and, 29.64% – associative bonds), with 206 interreflections excluded. The types of semantic relations of the conjugated classification codes were adjusted for 72 SRSTI headings. The study findings will be utilized for the book publication: “The system of interrelated classification codes: The semantic matches between SRSTI headings and UDC codes. Amendments and additions”.