Unique way to idetify quads

I imagine when you have multiple kids of the same gender and their all identical and not fraternal it can be difficult to know who's who I imagine but I don't know about doing this though to my child. I'd prefer some sort of band system. Do you think there's a better way to identify identical children rather than cutting their hair into a number? http://abcnews.go.com/blogs/lifestyle/2012/09/quadruplets-idd-by-numbers-shaved-onto-heads/