Said of a program or feature that is considered obsolescent and in
the process of being phased out, usually in favor of a specified
replacement. Deprecated features can, unfortunately, linger on for many
years. This term appears with distressing frequency in standards documents
when the committees writing the documents realize that large amounts of
extant (and presumably happily working) code depend on the feature(s) that
have passed out of favor. See also
dusty deck.
[Usage note: don't confuse this word with ‘depreciated’,
or the verb form ‘deprecate’ with ‘depreciate’.
They are different words; see any dictionary for discussion.]