Ain't IFAB? (International Football Association Board)

But the decision by the CSA clearly states that turbans, as well as smaller versions called patkas and keskis, are permitted as long as they are safe and “don’t pose a danger to the wearer and other participants.” The ruling was simply an extension of a 2012 decision by the International Football Association Board, the body that determines the laws of the game, that allowed Muslim girls to wear a modified version of the hijab.

http://www.montrealgazette.com/life/Quebec+soccer+body+break+silence+until+Wednesday/8510810/story.html