I learned about identifying Sikhs during my pre-9/11 university days because there were Sikhs attending the medical and engineering programs. (I was liberal arts; we know who got more value for their degree.
) Sikhs are a pleasant people who are a permanent religious minority and so they know about tolerance and patient explanations of one's beliefs to a suspicious audience of non-believers. A SIkh would never shoot me in the head because I opposed the spread of Sikh-ism. And they make nice curries.