There are a few new "features":

1. For functionality that is only possible or testable on certain server versions, there are specific files with an option/feature name appended. For example "aggregate-out.yml"

2. For these files, there is a field, minServerVersion, specifying the lower bound server version against which the test should be run. In other words, "run the test if server version >= minServerVersion.

3. There is potentially a field, maxServerVersion, which is the highest server version against which the test should be run. None of the files have this field yet, but I would suggest in implementing support for minServerVersion, you also implementing support for maxServerVersion. This field should be interpreted to mean "run this test if server version <= maxServerVersion."

4. If neither minServerVersion nor maxServerVersion are present, the test should succeed on any server version.

5. Collation is an added option to some tests. You'll need to update your test runners to parse the collation option.

Please let me know if you have any questions.