EARL Testcase Clarification

I need to state that a web page has failed a test and that the test is
required by an accessibility guideline.

I'm thinking that the earl:testId is used to specify the test.

Is the earl:Testcase used to specify the accessibility guideline that
requires the test?

Example:

<earl:Testcase rdf:resource=http://guidelines.org/a-guideline.html>
 <earl:testId rdf:resource=http://checks.org/test25.html />
 </earl:Testcase>

Thanks for your help.

Chris