Last modified: 2013-09-02 20:57:06 UTC
Otherwise users without CSS and JS (= text browsers, screen readers etc) see it. Inserting it with JS might be a solution. This may have pages jerking, but CentralAuth causes a bigger one. Anyway a small link won't affect page layout much if there's already something in the notice. This means, we need to check whether there's really a notice ( .text() != '' ) before creating the link.
I think the way to go might be to change the text link to a fixed-size close icon, as suggested (under "Constrained formatting") on https://www.mediawiki.org/wiki/Requests_for_comment/Dismissable_notices .