As the rate of research production accelerates, the ability to efficiently and unambiguously communicate judgements relating to the synthesis, evaluation, and use of scientific information becomes paramount. Scientific information can be viewed as a "layered infrastructure" of data, evidence, knowledge, and use. The GRADE approach serves as a de facto data standard in this infrastructure, reducing ambiguity in claims to knowledge (in the form of judgements of certainty in the evidence when answering research questions) and level of commitment to possible solutions to problems (in the form of strength of recommendations for interventions). However, the absence of a formalised terminology standard within GRADE limits the efficiency, rigour, consistency, and interoperability with which it is used. This GRADE concept paper outlines the potential benefits of a GRADE Ontology for the creators, educators, and users of systematic reviews, health guidelines, and health technology assessments, and the development of tools that help with conducting, finding, and summarising the same. It also presents the processes for the development and maintenance of the GRADE Ontology. [Abstract copyright: Copyright © 2025. Published by Elsevier Inc.]