The Journal on Data Semantics XIII is a scholarly publication that focuses on significant research and development work in the field of data semantics. This issue particularly addresses topics related to semantic data repositories and provides a comprehensive overview of innovative approaches and theories that support the formal definition of semantic content. The contributions in this volume highlight the advantages of viewing data repositories from a semantic perspective and offer valuable insights into future research directions. The target audience includes both researchers and experienced practitioners dealing with topics such as the semantic web, interoperability, knowledge representation, and artificial intelligence. The diversity of topics covered makes this journal an important resource for anyone engaged with the challenges and opportunities of data semantics.