It looks like there was a change on 19th August, 2014: https://github.com/w3c/webappsec/commit/b48b635f93a798da87c61e5b8c2d89d8b36567d8 https://github.com/w3c/w

It looks like there was a change on 19th August, 2014: https://github.com/w3c/webappsec/commit/b48b635f93a798da87c61e5b8c2d89d8b36567d8 https://github.com/w3c/webappsec/commit/b48b635f93a798da87c6... However, clicking the link to “Latest Version” at the top of the document you linked (from Dec 2015) takes you to the document I posted (from Aug 2014) so…who knows? It will require some testing to see what the browsers have actually implemented I guess.