A scene from Sir Arthur Conan Doyle’s Sherlock Holmes story, ‘The Red-Headed League’ keeps coming to mind. In the story, an ad has been placed in the paper offering work for a red-headed man. Later, we read of the long line of men curling down a London cobblestone street, waiting to be interviewed, their hair a marvelous range of hues from orange to auburn.

When I travel on the Bay Area Rapid transit, I sometimes see clusters of people who could create their own special leagues. The spike-heeled women. The bald men. People in fedoras. The young women carefully applying mascara, looking in the compact mirror. The league of the earbuds. The folks with one pant leg rolled up. The bare-legged. The krewe of the gray hair roots. The blondies. The men with hair combed straight back. The dreadlocked. The tattooed. The society of facial hardware. The sisterhood of the thin-haired. The men with the waistband of their underwear showing above their jeans.

Some people seem able to broadcast their identities through a single aspect of their appearances.

A couple of years ago when I was living in Louisiana, a town banned people from having any part of their underwear visible. So, if you were walking down the street, and a strip of your plaid boxers was visible above the waistband, however fully covered and cleanly dressed you were, you could be stopped and given a fine.

Last night in Berkeley, a lean young man standing on a skateboard was towed by a dog on a leash down a dark sidewalk.