In the Examples section.

The new Scenario Outline section below will run the scenario once per row in the Example table, substituting what's in the column for the placeholders in the scenario.

So what this will do, is try to grab / from all 4 mirrors, checking that they all return a 200, then do the same for /council-tax-reduction, then check that /search 503s and a page which should 404 actually 503s