There are actually a few ways that you can override this, but look at the Page.ClientTarget property. It should serve as a good starting point.
You shouldn't need to do that. If something is advertised as being compliant with a standard it should be 100% compliant. The developer should not have to do extra work.
It may seem minor, but for some it is important. Don't advertise a feature if that feature does not do what it is meant to do.