http://api.jquery.com/category/selectors/
"Borrowing from CSS 1–3, and then adding its own, jQuery offers a powerful set of tools for matching a set of elements in a document."
Now that we've gone all the way down the pedantry slide, have you anything of value to contribute, or was that it?
If you want to pick on something that claims compatibility, try Sizzle itself - http://sizzlejs.com/. In that case, you'll find a summary of alterations right at the top of its documentation https://github.com/jquery/sizzle/wiki .