metasyntactic variable n. A name used in examples and understood to stand for whatever thing is under discussion, or any random member of a class of things under discussion. The word foo is the canonical example. To avoid confusion, hackers never (well, hardly ever) use `foo' or other words like it as permanent names for anything. In filenames, a common convention is that any filename beginning with a metasyntactic-variable name is a scratch file that may be deleted at any time.

To some extent, the list of one's preferred metasyntactic variables is a cultural signature. They occur both in series (used for related groups of variables or objects) and as singletons. Here are a few common signatures: 


     foo, bar, baz, quux, quuux, quuuux...:
             MIT/Stanford usage, now found everywhere (thanks largely to early
             versions of this lexicon!).  At MIT (but not at Stanford), baz
             dropped out of use for a while in the 1970s and '80s. A common
             recent mutation of this sequence inserts qux before
             quux.
     bazola, ztesch:
             Stanford (from mid-'70s on).
     foo, bar, thud, grunt:
             This series was popular at CMU.  Other CMU-associated variables
             include gorp.
     foo, bar, fum:
             This series is reported to be common at XEROX PARC.
     fred, barney:
             See the entry for fred.  These tend to be Britishisms.
     toto, titi, tata, tutu:
             Standard series of metasyntactic variables among francophones.
     corge, grault, flarp:
             Popular at Rutgers University and among GOSMACS hackers.
     zxc, spqr, {wombat}:
             Cambridge University (England).
     shme
             Berkeley, GeoWorks, Ingres.  Pronounced /shme/ with a short /e/.
     foo, bar, zot
             Helsinki University of Technology, Finland.
     blarg, wibble
             New Zealand


   Of all these, only `foo' and `bar' are universal (and baz
   nearly so).  The compounds foobar and `foobaz' also enjoy
   very wide currency.  


   Some jargon terms are also used as metasyntactic names; barf
   and mumble, for example.  See also Commonwealth Hackish
   for discussion of numerous metasyntactic variables found in Great
   Britain and the Commonwealth.