FAULTY
adj. Same denotation as "bagbiting", "bletcherous", "losing", q.v., but the connotation is much milder.

FEATURE
n. 1. A surprising property of a program. Occasionally docu- mented. To call a property a feature sometimes means the author of the program did not consider the particular case, and the program makes an unexpected, although not strictly speaking an incorrect response. See BUG. "That's not a bug, that's a feature!" A bug can be changed to a feature by documenting it.
2. A well-known and beloved property; a facility. Sometimes features are planned, but are called crocks by others. An approximately correct spectrum:
(These terms are all used to describe programs or portions thereof,
except for the first two, which are included for completeness.)
CRASH STOPPAGE BUG SCREW LOSS MISFEATURE
CROCK KLUGE HACK WIN FEATURE PERFECTION
(The last is never actually attained.)

FEEP
1. n. The soft bell of a display terminal (except for a VT-52!); a beep.
2. v. To cause the display to make a feep sound. TTY's do not have feeps. Alternate forms: BEEP, BLEEP, or just about anything suitably onomatopoeic. The term BREEDLE is sometimes heard at SAIL, where the terminal bleepers are not particularly "soft" (they sound more like the musical equivalent of sticking out one's tongue). The "feeper" on a VT-52 has been compared to the sound of a '52 Chevy stripping its gears.

FENCEPOST ERROR
n. The discrete equivalent of a boundary condition. Often exhibited in programs by iterative loops. From the following problem: "If you build a fence 100 feet long with posts ten feet apart, how many posts do you need?" (Either 9 or 11 is a better answer than the obvious 10.)

FINE (WPI)
adj. Good, but not good enough to be CUSPY. [The word FINE is used elsewhere, of course, but without the implicit comparison to the higher level implied by CUSPY.]

FLAG DAY
[from a bit of Multics history involving a change in the ASCII character set originally scheduled for June 14, 1966] n. A software change which is neither forward nor backward compatible, and which is costly to make and costly to revert. "Can we install that without causing a flag day for all users?"

FLAKEY
adj. Subject to frequent lossages. See LOSSAGE.

FLAME
v. To speak incessantly and/or rabidly on some relatively uninteresting subject or with a patently ridiculous attitude. FLAME ON: v. To continue to flame. See RAVE. This punning reference to Marvel comics' Human Torch has been lost as recent usage completes the circle: "Flame on" now usually means "beginning of flame".

FLAP
v. To unload a DECtape (so it goes flap, flap, flap...). Old hackers at MIT tell of the days when the disk was device 0 and microtapes were 1, 2,... and attempting to flap device 0 would instead start a motor banging inside a cabinet near the disk!

FLAVOR
n. 1. Variety, type, kind. "DDT commands come in two flavors." See VANILLA.
2. The attribute of causing something to be FLAVORFUL. "This convention yields additional flavor by allowing one to..."
3. On the LispMachine, an object-oriented programming system ("flavors"); each class of object is a flavor.

FLAVORFUL
adj. Aesthetically pleasing. See RANDOM and LOSING for antonyms. See also the entry for TASTE.

FLUSH
v. 1. To delete something, usually superfluous. "All that nonsense has been flushed." Standard ITS terminology for aborting an output operation.
2. To leave at the end of a day's work (as opposed to leaving for a meal). "I'm going to flush now." "Time to flush." 3. To exclude someone from an activity.

FOO
1. [from Yiddish "feh" or the Anglo-Saxon "fooey!"] interj. Term of disgust.
2. [from FUBAR (Fucked Up Beyond All Recognition), from WWII, often seen as FOOBAR] Name used for temporary programs, or samples of three-letter names. Other similar words are BAR, BAZ (Stanford corruption of BAR), and rarely RAG. These have been used in Pogo as well.
3. Used very generally as a sample name for absolutely anything. The old `Smokey Stover' comic strips often included the word FOO, in particular on license plates of cars. MOBY FOO: See MOBY.

FRIED
adj. 1. Non-working due to hardware failure; burnt out.
2. Of people, exhausted. Said particularly of those who continue to work in such a state. Often used as an explanation or excuse. "Yeah, I know that fix destroyed the file system, but I was fried when I put it in."

FROB
1. n. (MIT) The official Tech Model Railroad Club definition is "FROB = protruding arm or trunnion", and by metaphoric extension any somewhat small thing. See FROBNITZ.
2. v. Abbreviated form of FROBNICATE.

FROBNICATE
v. To manipulate or adjust, to tweak. Derived from FROBNITZ (q.v.). Usually abbreviated to FROB. Thus one has the saying "to frob a frob". See TWEAK and TWIDDLE. Usage: FROB, TWIDDLE, and TWEAK sometimes connote points along a continuum. FROB connotes aimless manipulation; TWIDDLE connotes gross manipulation, often a coarse search for a proper setting; TWEAK connotes fine-tuning. If someone is turning a knob on an oscilloscope, then if he's carefully adjusting it he is probably tweaking it; if he is just turning it but looking at the screen he is probably twiddling it; but if he's just doing it because turning a knob is fun, he's frobbing it.

FROBNITZ, pl. FROBNITZEM (frob'nitsm)
n. An unspecified physical object, a widget. Also refers to electronic black boxes. This rare form is usually abbreviated to FROTZ, or more commonly to FROB. Also used are FROBNULE, FROBULE, and FROBNODULE. Starting perhaps in 1979, FROBBOZ (fruh-bahz'), pl. FROBBOTZIM, has also become very popular, largely due to its exposure via the Adventure spin-off called Zork (Dungeon). These can also be applied to non-physical objects, such as data structures

FROG (variant: PHROG)
1. interj. Term of disgust (we seem to have a lot of them).
2. Used as a name for just about anything. See FOO.
3. n. Of things, a crock. Of people, somewhere inbetween a turkey and a toad.
4. Jake Brown (FRG@SAIL).
5. FROGGY: adj. Similar to BAGBITING (q.v.), but milder. "This froggy program is taking forever to run!"

FROTZ
1. n. See FROBNITZ.
2. MUMBLE FROTZ: An interjection of very mild disgust.

FRY
v. 1. To fail. Said especially of smoke-producing hardware failures.
2. More generally, to become non-working. Usage: never said of software, only of hardware and humans. See FRIED.

FTP (spelled out, NOT pronounced "fittip")
1. n. The File Transfer Protocol for transmitting files between systems on the ARPAnet.
2. v. To transfer a file using the File Transfer Program. "Lemme get this copy of Wuthering Heights FTP'd from SAIL."

FUDGE
1. v. To perform in an incomplete but marginally acceptable way, particularly with respect to the writing of a program. "I didn't feel like going through that pain and suffering, so I fudged it."
2. n. The resulting code.

FUDGE FACTOR
n. A value or parameter that is varied in an ad hoc way to produce the desired result. The terms "tolerance" and "slop" are also used, though these usually indicate a one-sided leeway, such as a buffer which is made larger than necessary because one isn't sure exactly how large it needs to be, and it is better to waste a little space than to lose completely for not having enough. A fudge factor, on the other hand, can often be tweaked in more than one direction. An example might be the coefficients of an equation, where the coefficients are varied in an attempt to make the equation fit certain criteria.