[CMU, Tektronix: from backward compatibility] A property of hardware
or software revisions in which previous protocols, formats, layouts,
etc. are irrevocably discarded in favor of `new and improved'
protocols, formats, and layouts, leaving the previous ones not merely
deprecated but actively defeated. (Too often, the old and new
versions cannot definitively be distinguished, such that lingering
instances of the previous ones yield crashes or other infelicitous
effects, as opposed to a simple "version 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}.
[glossary]
[Reference(s) to this entry by made by: {connector conspiracy}{flag day}]