Various sizes of circle stickers.
It used to stand for Black Reparations Fund, but it turns out we can't legally do that, so now it means, "Bike Riding's Fun!" or "Bikes-R-Fantastic." In either case, we donate all BRF funds collected from the sale of these stickers to charity.
We put these funds into a separate bank account, not connected to the general Rivendell one. We hope you'll toss a sheet into your basket.
Hot tip 4 cheapskates: One of these over an existing button turns said sad existing button into a $5 BRF button. It's not as slick, it takes on a slight wrinkle as it attempts to cover the curve, but it basically works well.