Original by Mark Means.
The Crying Freeman has this schtick, and any character can have it in almost any juncture. It might be useful for those on the wrong side of the law (Spies, Killers, Gamblers), those who like their privacy (Masked Avengers without the mask) and those who may want to protect their families (Everyday Hero, Martial Artist, Old Master).
This schtick gives a sort of anonymity. Your features are average and forgettable (even if you're attractive).
Gamemaster characters can't seem to remember just exactly what you looked like when giving a description. ("He looked kinda' tall, in a short way. I just can't remember.") They know someone was there, but they just can't think of what he looked like. Maybe they weren't paying attention or however else you want to explain it. (If you even want to explain it).