The problems of using personal data that arise from the inaccuracy of terms, both in information activities and in information law, are discussed. The arguments that can allow the creation of a thesaurus of personal data and their information ontology are presented. The results of an analysis based on the category-tensor approach make it possible to intensify the discussion on this topic. This indicates the need for interdisciplinary efforts to create an information ontology of personal data, without which digital transformation is impossible. The first version of the N-dimensional categorical model of personal data and operations with them is proposed, and the categories of a person and personal data are defined.