mismatch" message.) A backwards compatible change, on the other
hand, allows old versions to coexist without crashes or error
messages, but too many major changes incorporating elaborate
backwards compatibility processing can lead to extreme {software
bloat}. See also {flag day}.

:BAD: /B-A-D/ /adj./ [IBM: acronym, `Broken As Designed']
Said of a program that is {bogus} because of bad design and
misfeatures rather than because of bugginess. See {working as
designed}.

:Bad Thing: /n./ [from the 1930 Sellar & Yeatman parody "1066
And All That"] Something that can't possibly result in
improvement of the subject. This term is always capitalized, as in
"Replacing all of the 9600-baud modems with bicycle couriers would
be a Bad Thing". Oppose {Good Thing}. British correspondents
confirm that {Bad Thing} and {Good Thing} (and prob.
therefore {Right Thing} and {Wrong Thing}) come from the book
referenced in the etymology, which discusses rulers who were Good
Kings but Bad Things. This has apparently created a mainstream
idiom on the British side of the pond.

:bag on the side: /n./ [prob. originally related to a
colostomy bag] An extension to an established hack that
is supposed to add some functionality to the original. Usually
derogatory, implying that the original was being overextended and
should have been thrown away, and the new product is ugly,
inelegant, or bloated. Also /v./ phrase, `to hang a bag on the
side
[of]'. "C++? That's just a bag on the side of C ...."