For those who might be having a bit of a moment, like I was, no, they do not dangle printed punctuation from a string in the fries like you often see in elementary school classrooms.
It's when you put the punctuation outside the normal margins. Bullets often do this, but it's exceptionally classy to do it with opening punctuation like " ' etc.
For web designers: http://css-tricks.com/almanac/properties/h/hanging-punctuation/