:con: [from SF fandom] /n./ A science-fiction convention. Not
used of other sorts of conventions, such as professional meetings.
This term, unlike many others of SF-fan slang, is widely recognized
even by hackers who aren't {fan}s. "We'd been corresponding on
the net for months, then we met face-to-face at a con."

:condition out: /vt./ To prevent a section of code from being
compiled by surrounding it with a conditional-compilation directive
whose condition is always false. The {canonical} examples of
these directives are `#if 0' (or `#ifdef notdef', though
some find the latter {bletcherous}) and `#endif' in C.
Compare {comment out}.

:condom: /n./ 1. The protective plastic bag that accompanies
3.5-inch microfloppy diskettes. Rarely, also used of (paper) disk
envelopes. Unlike the write protect tab, the condom (when left on)
not only impedes the practice of {SEX} but has also been shown
to have a high failure rate as drive mechanisms attempt to access
the disk -- and can even fatally frustrate insertion. 2. The
protective cladding on a {light pipe}. 3. `keyboard condom':
A flexible, transparent plastic cover for a keyboard, designed to
provide some protection against dust and {programming fluid}
without impeding typing. 4. `elephant condom': the plastic
shipping bags used inside cardboard boxes to protect hardware in
transit. 5. /n. obs./ A dummy directory `/usr/tmp/sh', created
to foil the Great Worm by exploiting a portability bug in one
of its parts. So named in the title of a comp.risks article by
Gene Spafford during the Worm crisis, and again in the text of
"The Internet Worm Program: An Analysis", Purdue Technical
Report CSD-TR-823. See {Great Worm, the}.