As in Sinister Footware.............. [ame=http://www.youtube.com/watch?v=w3jlwaUk1pQ]YouTube - Frank Zappa - Sinister Footwear II (live in NYC, 1981)[/ame]
Which shows you just how long ago the prejudice against left-handed people existed. In the absence of more easily-identified differences, anything will do..... I worked in a factory where, when the only non-Caucasian left, the guy with ginger hair got picked on! My father was probably left-handed though that was unacceptable to his Victorian parents so he had to learn to write with his right hand. He used his left hand for everything instinctive, like holding a screwdriver.