I beg your pardon? I take exception to that.
I was merely pointing out that :after is perfectly valid css 2.1 and there is no reason to use ::after as long as you are supporting IE8 (which quite a lot of us still do). Telling people to use the double colon syntax on CSS 2.1 pseudo elements will cause those pages to break in IE8 which is why I chimed in as you are not the first to recommend this.
The html5 boilerplate and bootstrap3 all use the single colon syntax for :after and :before and I recommend that everyone continues to use this format for a couple of more years at least.