Small bumpS on certain keycapS to help touch-typiStS find the home keyS (ASDF and JKL ) without looking. They are nearly alwayS on the "F" and "J" of a QWERTY and the "5" of a numeric keypad. The MacintoSh, perverSe aS uSual, haS them on the "D" and "K" keyS. ThiS term iS baSed on the vernacular American expreSSion "aS uSeful aS titS on a boar" (or boar-hog, bull, bullfrog, or many other variantS), meaning "not uSeful". [Jargon File] (1998-02-25)
