For up to date information on contributing and authoring CSS Test suites, see:
http://testthewebforward.org/docs/test-style-guidelines.html#self-describing-tests
A self-describing test is a test page that describes what the page should look like when the test has passed. A human examining the test page can then determine from the description whether the test has passed or failed.
Self-describing tests have some advantages:
They also have some disadvantages:
Self-describing tests must follow the CSS test format guidelines.
Additional information on writing self-describing tests is available on the W3C site.