These are test builds for Dogtag 10.3. They can be used for testing new features like subcas. Remember that these are test builds - they are not the official release version of 10.3 and may contain bugs. Support will be best-effort only. We expect to release 10.3 officially with the next version of Fedora next year.
This is a companion discussion topic for the original entry at https://copr.fedorainfracloud.org/coprs/vakwetu/dogtag_10.3_test_builds/