The Jargon File, Version 2.9.10, 01 Jul 1992. Various

`cons' is the most fundamental operation for building structures. It takes any two objects and returns a `dot-pair' or two-branched tree with one object hanging from each branch. Because the result of a cons is an object, it can be used to build binary trees of any shape and complexity. Hackers think of it as a sort of universal constructor, and that is where the jargon meanings spring from.

      :considered harmful: adj. Edsger W. Dijkstra's note in the March 1968 `Communications of the ACM', "Goto Statement Considered Harmful", fired the first salvo in the structured programming wars. Amusingly, the ACM considered the resulting acrimony sufficiently harmful that it will (by policy) no longer print an article taking so assertive a position against a coding practice. In the ensuing decades, a large number of both serious papers and parodies have borne titles of the form "X considered Y". The structured-programming wars eventually blew over with the realization that both sides were wrong, but use of such titles has remained as a persistent minor in-joke (the `considered silly' found at various places in this lexicon is related).

      :console:: n. 1. The operator's station of a {mainframe}. In times past, this was a privileged location that conveyed godlike powers to anyone with fingers on its keys. Under UNIX and other modern timesharing OSes, such privileges are guarded by passwords instead, and the console is just the {tty} the system was booted from. Some of the mystique remains, however, and it is traditional for sysadmins to post urgent messages to all users from the console (on UNIX, /dev/console). 2. On microcomputer UNIX boxes, the main screen and keyboard (as opposed to character-only terminals talking to a serial port). Typically only the console can do real graphics or run {X}. See also {CTY}.

      :console jockey: n. See {terminal junkie}.

      :content-free: [by analogy with techspeak `context-free'] adj. Used of a message that adds nothing to the recipient's knowledge. Though this adjective is sometimes applied to {flamage}, it more usually connotes derision for communication styles that exalt form over substance or are centered on concerns irrelevant to the subject ostensibly at hand. Perhaps most used with reference to speeches by company presidents and other professional manipulators. "Content-free? Uh…that's anything printed on glossy paper." See also {four-color glossies}. "He gave a talk on the implications of electronic networks for postmodernism and the fin-de-siecle aesthetic. It was content-free."