I went to the Sports Basement today (I know; I'm practically an Olympian) in my continued quest to find some kind of sweat pants that don't look like they were developed as an anatomical guide (seriously. yoga pants = too much information) and to replace my swimcap. There are various kinds of caps, each of which is helpfully on display with a little sign explaining its merits. The sign under the one I purchased said "Gentile on hair."
I'm not even entirely sure what that would entail, but, to be on the safe side, I borrowed a Sharpie from the clerk and now the Jews of San Francisco are free to swim with non-denominational caps.