I was surprised by this, but at least as early as September 2008: https://github.com/whatwg/html/commit/c67bb312ac44737c6c175b16a7161e06a269c680 https://github.

I was surprised by this, but at least as early as September 2008: https://github.com/whatwg/html/commit/c67bb312ac44737c6c175b16a7161e06a269c680 https://github.com/whatwg/html/commit/c67bb312ac44737c6c175b...