bckrnym = "acronym contrived to match" [sc] e.g. "Png"

rtrnym = "constructed after the fact" [sc] e.g. "Old Testament" http://en.wikipedia.org/wiki/Retronym

A retronym is a type of neologism coined for an old object or concept whose original name has come to be used for something else, is no longer unique, or is otherwise inappropriate or misleading.

e-mail, as used today, is an example of a neologism

A neologism is a word, term, or phrase that has been recently created (or "coined"), often to apply to new concepts, to synthesize pre-existing concepts, or to make older terminology sound more contemporary.

The word retronym also refers to an acronym constructed after the fact (a backronym), such as Perl.

"PERL" (for Practical Extraction and Report Language). Although the expansion has prevailed in many of today's manuals, including the official Perl man page, it is merely a backronym. The name does not officially stand for anything, so spelling it in all caps is incorrect and is considered a shibboleth (label of outsiders) in the Perl community.

from the Hebrew word שיבולת (other Semitic languages, e.g., Arabic: سنبلة /sunbulah/, Dialectal Arabic [Yemenite]: سبولة /sabūlah/), which literally means the part of a plant containing grains, such as an ear of corn or a stalk of grain ^[2] or, in different contexts, "stream, torrent"^{[3] [4]} (the latter meaning is not in use in Modern Hebrew). It derives from an account in the Hebrew Bible, in which pronunciation of this word was used to distinguish members of a group (the Ephraimites) whose dialect lacked a /ʃ/ sound (as in shoe) from members of a group (the Gileadites) whose dialect did include such a sound.

In 2000, the American Heritage Dictionary, 4th edition was the first major dictionary to include the word retronym.^[5]

ping - Wikipedia, the free encyclopedia Later David L. Mills provided a backronym, "Packet InterNet Grouper (Groper)" (sometimes also defined as "Packet Inter-Network Groper). ... en.wikipedia.org/wiki/Ping FastFacts on Ping The computer acron ym (for Packet Internet or Inter-Network Groper) was contrived to match the submariners' term for the sound of a returned sonar pulse. ... searchnetworking.techtarget.com/generic/0,295582,sid7_gci1130030,00.html