No, it's a selector, but one that can include the actual text in the page. So instead of having to select based on a pre-existing anchor, like `http://site.com/page#anchor`, you can link to `http://site.com/page#understanding+his+correctly` (though that's not their format). No need to alter the markup.

Though, I'm curious how this works when text is broken apart over spans or divs.