Open data licenses
When it is possible to publish and make data openly accessible, the data should be labeled with a license that informs everyone that they can access, use, and share it.
Creative Commons
There are many different licenses, so choose one that is already widely used to increase reuse in accordance with the FAIR principles. Creative Commons licenses are often used for open content. The most open license is CC BY 4.0 (besides CC0). It allows sharing, modification, and commercial use, provided that the creator is credited. Version 4.0 includes data licensing. If you publish data in services like Zenodo or DORIS, it will automatically be assigned the CC BY 4.0 license unless you choose a different license yourself.
Read more about licenses and research data at Researchdata.se