The checking I just did, which I actually find hard to believe, suggest that it's not just IE8 throwing an exception on `div.querySelectorAll(":enabled")`, but IE8-11+ (that's right, even the latest available IE rejects `:disabled` and `:enabled`)! If that's correct, then this whole additional `assert` is unnecessary because any selector containing those tokens will fail and fall into our engine anyway. Unless `isDisabled` logic can fix another broken client, it looks like all you need to do here is update the range in the [L653](https://github.com/cmcnulty/sizzle/blob/sizzle-174/src/sizzle.js#L653) support comment.

I think that also answers your confusion about the preceding assert (IE8 executes nothing after `div.querySelectorAll(":enabled")`, including `rbuggyQSA.push( ":enabled", ":disabled" )`, and _only_ Opera 10-11 execute `rbuggyQSA.push(",.*:")` because other clients will have errored on `div.querySelectorAll("*,:x")` [which you correctly identify as independent of the div content]), but feel free to follow up with other questions. There's lots of pro-compression shortcuts in `assert`, like exception trapping and automatic `div` creation.