Date: Feb. 8, 1999
Link: http://www.w3.org/Style/CSS/Test/
Source Author or Organization: W3C

Excerpted from web site: "The CSS1 Test Suite is provided as a way for vendors and page authors to test their browser's conformance to the CSS1 specification. This test suite is organized around individual properties of Cascading Style Sheets, Level 1 (CSS1). In order to use it most effectively, you will NEED to make sure that you have completely read and understood the contents of Prologue before you start testing any user agent."

"For each property, there is at least one page which tests the property's values in various combinations, using HTML 4.0 markup. The test pages are broken out into a number of sections which reflect the structure of the CSS1 specification itself, in addition to a Prologue and a few appendicies."