T215470 added a custom copyright footer to Wikimedia Commons which mentions the CC0 nature of structured data. Its current version reads as follows (emphasis added):
Files are available under licenses specified on their description page. All structured data from the file and property namespaces is available under the Creative Commons CC0 License; all unstructured text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and the Privacy Policy.
There is no property namespace on Wikimedia Commons, so I don’t think it makes sense to mention it here. I suggest to remove it.