tired iron
= T =
TLA
tits on a keyboard n.
Small bumps on certain keycaps to
keep touch-typists registered. Usually on the 5 of a numeric
keypad, and on the F and J of a QWERTY keyboard;
but older Macs had them on the D and
K keys (this changed in 1999).
--Jargon File, autonoded by rescdsk.