jargon, node: metasyntactic variable

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metasyntactic variable

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.
     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/.
     snork
          Brown University, early 1970s.
     foo, bar, zot
          Helsinki University of Technology, Finland.
     blarg, wibble
          New Zealand.
     toto, titi, tata, tutu
          France.
     pippo, pluto, paperino
          Italy.  Pippo /pee'po/ and Paperino /pa-per-ee'-no/ are the
          Italian names for Goofy and Donald Duck.
     aap, noot, mies
          The Netherlands.  These are the first words a child used to
          learn to spell on a Dutch spelling board.

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.

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