Acronym for Knowledge In, Bullshit Out. A summary of what happens 
whenever valid data is passed through an organisation that 
deliberately or accidentally disregards or ignores its significance. 
Consider, for example, what an advertising campaign can do with a 
product's actual
specifications. Compare GIGO; see also SNAFU principle.

1. Garbage In, Garbage Out. A reference to the fact that computers, 
unlike humans, will unquestioningly process the most nonsensical of 
input data and produce nonsensical output. Of course a properly 
written program will reject input data that is obviously erroneous 
but such checking is not always easy to specify and is tedious to 

GIGO is usually said in response to users who complain that a program 
did not "do the right thing" when given imperfect input or otherwise 
mistreated in some way. Also commonly used to describe failures in 
human decision making due to faulty, incomplete, or imprecise data.

2. Garbage In, Gospel Out. This more recent expansion is a sardonic 
comment on the tendency human beings have to put excessive trust in 
"computerised" data.

see also KIBO

The slang word snafu is an army acronym for "situation normal: all fucked up".
It has crept into civilian usage, unlike its stronger variant tarfu. 
The penultimate fu word fubar is sometimes believed to have led to 
the computer programming term foobar, but it appears more likely that 
it evolved independently.