[vasergen]

I think it is a bit different, because with "use strict" we have already some rules and the typeof null is object there and now is too late to change that. The same for any other feature we don't want to have in a language.

Maybe it was a mistake to introduce "use strict" without any other identifier, we need "use strict" with a version to be able to deprecate things and eventually remove from JS. Then JS engine could read it in the beginning of the file and know which version of js it is. Because in current JS we can only add new features without removing them. I am sure it is very complicated problem since we don't want to break the internet and browsers still have to work with old websites.