A core catcher is a device provided to catch the molten core material (corium) of a nuclear reactor in case of a nuclear meltdown and prevent it from escaping the containment building.

An international mobile subscriber identity-catcher, or IMSI-catcher, is a telephone eavesdropping device used for intercepting mobile phone traffic and tracking location data of mobile phone users. Essentially a "fake" mobile tower acting between the target mobile phone and the service provider's real towers, it is considered a man-in-the-middle (MITM) attack.

A spring is an elastic object that stores mechanical energy. Springs are typically made of spring steel.

Jersey finger, also known as rugby finger, is a finger-related tendon injury that is common in sport and can result in permanent loss of flexion of the end of the finger if not surgically repaired. The injury is common when one player grabs another's jersey with the tips of one or more fingers while that player is pulling or running away.

<operating system> On Unix systems that support finger, the ".plan" file in a user's home directory is displayed when the user is fingered. This feature was originally intended to be used to keep potential fingerers apprised of one's location and near-future plans, but has been turned almost universally to humorous and self-expressive purposes (like a sig block). See also Hacking X for Y. A later innovation in plan files was the introduction of "scrolling plan files" which are one-dimensional animations made using only the printable ASCII character set, {carriage return} and line feed, avoiding terminal specific {escape sequences}, since the finger command will (for security reasons; see letterbomb) not pass the escape character. Scrolling .plan files have become art forms in miniature, and some sites have started competitions to find who can create the longest running, funniest, and most original animations. A compiler (ASP) is available on Usenet for producing them. Typical animation components include: Centipede: mmmmme Lorry/Truck: oo-oP Andalusian Video Snail: _@/ In the mid-1990s WWW home pages largely supplanted .plan files, providing a much richer forum for the publication of personal minutiae and digital creativity. See also twirling baton. [Jargon File] (1998-01-16)

<operating system> See plan file.

main memory

In computer networking, the Name/Finger protocol and the Finger user information protocol are simple network protocols for the exchange of human-oriented status and user information.

<storage> (Or "core") An early form of non-volatile storage built (by hand) from tiny rings of magnetisable material threaded onto very fine wire to form large (e.g. 13"x13" or more) rectangluar arrays. Each core stored one bit of data. These were sandwiched between printed circuit boards(?). Sets of wires ran horizontally and vertically and where a vertical and horizontal wire crossed, a core had both wires threaded through it. A single core could be selected and magnetised by passing sufficient current through its horizontal and vertical wires. A core would retain its magnetisation until it was re-magnetised. The two possible polarities of magnetisation were used to represent the binary values zero and one. A third "sense" wire, passed through the core and, if the magnetisation of the core was changed, a small pulse would be induced in the sense wire which could be detected and used to deduce the core's original state. Some core memory was immersed in a bath of heated oil to improve its performance. Core memory was rendered obsolete by semiconductor memory. For example, the 1970s-era NCR 499 had two boards, each with 16 kilobytes of core memory. (1996-03-04)