Even though one of the three stylesheets linked to this document cannot be received, the UA must display the document using the stylesheets that it can retrieve. This means the line of text below should be red when the document loads:
This is the line of text in question.
The UA must provide a mechanism for selection of alternate stylesheets. Therefore, the user must be presented with the ability to change the current stylesheet from "Original Stylesheet" to "Alternate Stylesheet." When this is done, the above paragraph will turn green. If this cannot be done, then the UA is not in conformance with the CSS2 Recommendation. See Ian Hickson's importtest for more tests of alternate stylesheets, based on HTML 4.0 and CSS.
(Back to CSS Testing Information, David Baron)