Operationalization of terminology for IT applications has revived the Wüsterian approach. The conceptual dimension once more prevails after taking back seat to specialised lexicography. This is demonstrated by the emergence of ontology in terminology. While the Terminology Principles as defined in Felber’s manual and the ISO standards remain at the core of traditional terminology, their computational implementation raises some issues. In this lecture, while reiterating their importance, we will be re-examining these Principles from a dual perspective: that of logic in the mathematical sense of the term and that of epistemology as in the theory of knowledge. We will thus be clarifying and describing some of them so as to take into account advances in knowledge engineering (ontology) and formal systems (logic). The notion of ontoterminology, terminology whose conceptual system is a formal ontology, results from this approach. The consequences of this new notion on the terminological work will be presented.