In the Lisp Machine world in the early '80s, one guy's first car had HLRZ as his vanity plate, that's the PDP-10 instruction that implements the CAR (IBM 704 Co

In the Lisp Machine world in the early '80s, one guy's first car had HLRZ as his vanity plate, that's the PDP-10 instruction that implements the CAR (IBM 704 Contents of Address Register) operation, which gets you the first element in a list, and his second, or another's, was CADR, which gets you the second element, and was also the name of the 2nd generation, beyond the prototype Lisp Machine that was manufactured in small quantities by MIT and LMI.