Spec is here:
Chrome and Firefox both support it.
This would be amazing to have. It would solve so many currently complex problems and is relatively low hanging fruit. It's now in all the other browsers.
Please implement this:
David Storey [MSFT] commented
Thomas Darling commented
Please implement this. It is such a simple thing, and it solves a pretty big problem when building SPA's - trying to work around the default browser behavior is currently a nightmare.