Test case: data:text/html,<!doctype html> <quasit style="display:block" align=right>Test</quasit> In IE9 and Firefox 8.0a2, the word "Test" is left-aligned. In Chrome 15 dev and Opera 11.50, it's right-aligned. The HTML specification says that align should only work on certain elements, like IE/Gecko: http://www.whatwg.org/specs/web-apps/current-work/multipage/rendering.html I don't know what the exact list should be, though. I didn't test what elements IE/Gecko respect it on.
Safari and Chrome match behavior here.