Matthias focused on enhancing catalog data quality for the ConductionNL/openregister repository during May 2025. He delivered a comprehensive update that refined enumerations, added new entries, adjusted strings, and removed or cleaned up a format URI field to improve data accuracy and consistency. Working primarily with JSON and leveraging strong data management skills, Matthias applied structured updates and thorough validation across the dataset. No major bugs were reported or fixed during this period, as the work centered on proactive data-quality improvements. His approach demonstrated careful version control and attention to detail, resulting in a more reliable and maintainable catalog.