At UFZ, spatial research data are managed and published through the spatial data infrastructure spatial.IO (https://zenodo.org/records/17347355).

Within spatial.IO, GeoNetwork (https://geonetwork-opensource.org/) is used as the central system for metadata cataloging and for assigning DOIs to datasets.

As part of improving interoperability, the UFZ GeoNetwork was registered for metadata harvesting, specifically for the Ocean Data and Information System (ODIS) (https://odis.org/).

During the registration and harvesting process, it became apparent that while the datasets themselves were already assigned licenses for data reuse, the metadata records lacked an independent and clearly defined license.

This raised an important question: How should UFZ metadata be licensed, both within the GeoNetwork and in a broader institutional context?

The issue was discussed within the UFZ Research Data Management (RDM) team. Two main options were considered:

• Enables unrestricted reuse of metadata
• Facilitates harvesting by machines, crawlers, and aggregators
• Reduces legal barriers for reuse and redistribution

• Ensures attribution to UFZ
• Maintains visibility and credit for the metadata creators

To support the decision-making process, UFZ aligned its approach with established data infrastructures, including:

• PANGAEA (https://www.pangaea.de/)
• Europeana (https://www.europeana.eu/en)

In particular, Europeana's detailed explanation of metadata licensing was highly influential: https://www.europeana.eu/en/rights/usage-guidelines-for-metadata

UFZ decided to apply the CC0 license to its metadata.

This approach maximizes openness and technical reuse, especially for metadata harvesting and aggregation. At the same time, UFZ explicitly requests appropriate attribution, even though it is not legally required under CC0.

In practice:

• Metadata in the UFZ GeoNetwork are published under CC0
• Users are asked to credit UFZ in an appropriate manner when reusing metadata
• Information about the license and attribution request is clearly documented within GeoNetwork

All data holders contributing to the UFZ GeoNetwork were informed about this change. The applied license and the request for attribution were made transparent directly within the metadata records.

We recommend that other research centres and data infrastructures consider a similar approach-using CC0 for metadata while encouraging attribution-wherever this aligns with their institutional goals and legal frameworks.

For questions or further information, please contact: Johann Wurz (johann.wurz@ufz.de)