Ok, I'm a dork. Help!!!

[JennK13]

My Trek, Giant and the stock wheel set on my Fuji all have them - only the Easton wheel set I bought after market doesn't have one. I'm with mumbles on where the term came from

And as for removing reflectors, too, the wrench at the LBS did take the one off the rear wheel of my Fuji while doing a minor repair in the field. I'm all about visibility, and my commuter lights up like a dang Christmas tree!!