Ghislain Atemezing worked on the opengeospatial/ontology-crs repository, delivering clarifications to the Coordinate Reference System ontology by introducing explicit disjointness relationships between key CRS-related classes. He focused on enhancing semantic clarity and logical consistency, updating alignment.csv to enforce disjointness between VerticalCoordinateSystem and OrdinalCoordinateSystem, as well as between Datum and CRS. Using ontology engineering and semantic web technologies, Ghislain ensured that these changes improved reasoning reliability and interoperability across geospatial datasets. His work demonstrated careful ontology modeling, CSV alignment, and Git-based traceability, resulting in reproducible semantic changes that support downstream validation and adherence to geospatial standards.