Prof. Yury N. Stolyarov’s contribution to the development of terminology and conceptual framework of document and information sciences is emphasized. Yury Stolyarov stood at the origins of documentology; however, there is still the need for intensive development of the discipline methodology. We have to understand the conventionality of scientific constructs at the theoretical (supra-empirical) level of research as the variability in building of theoretical schemes models, conceptual frameworks, and concept naming. Concept conventionality is about choosing the optimum meaning of the term for problem solution, elimination of disproportionalities of constructs in a certain field of knowledge. The conventionality of term formation in the context of the concept well-reasoned to eliminate disproportionality, allows the choice of the term not necessarily the most motivated for expressing the concept.