canonical

canonical adj.  [historically, `according to religious law']
   The usual or standard state or manner of something.  This word has
   a somewhat more technical meaning in mathematics.  Two formulas
   such as 9 + x and x + 9 are said to be equivalent
   because they mean the same thing, but the second one is in
   `canonical form' because it is written in the usual way, with the
   highest power of x first.  Usually there are fixed rules you
   can use to decide whether something is in canonical form.  The
   jargon meaning, a relaxation of the technical meaning, acquired its
   present loading in computer-science culture largely through its
   prominence in Alonzo Church's work in computation theory and
   mathematical logic (see {Knights of the Lambda Calculus}).
   Compare {vanilla}.

   This word has an interesting history.  Non-technical academics do
   not use the adjective `canonical' in any of the senses defined
   above with any regularity; they do however use the nouns `canon'
   and `canonicity' (not **canonicalness or **canonicality). The
   `canon' of a given author is the complete body of authentic works
   by that author (this usage is familiar to Sherlock Holmes fans as
   well as to literary scholars).  `*The* canon' is the body of
   works in a given field (e.g., works of literature, or of art, or of
   music) deemed worthwhile for students to study and for scholars to
   investigate.

   The word `canon' derives ultimately from the Greek
   `kanon'
   (akin to the English `cane') referring to a reed.  Reeds were used
   for measurement, and in Latin and later Greek the word `canon'
   meant a rule or a standard.  The establishment of a canon of
   scriptures within Christianity was meant to define a standard or a
   rule for the religion.  The above non-techspeak academic usages
   stem from this instance of a defined and accepted body of work.
   Alongside this usage was the promulgation of `canons' (`rules')
   for the government of the Catholic Church.  The techspeak usages
   ("according to religious law") derive from this use of the Latin
   `canon'.

   Hackers invest this term with a playfulness that makes an ironic
   contrast with its historical meaning.  A true story: One Bob
   Sjoberg, new at the MIT AI Lab, expressed some annoyance at the
   incessant use of jargon.  Over his loud objections, GLS and RMS
   made a point of using as much of it as possible in his presence,
   and eventually it began to sink in.  Finally, in one conversation,
   he used the word `canonical' in jargon-like fashion without
   thinking.  Steele: "Aha!  We've finally got you talking jargon
   too!"  Stallman "What did he say?"  Steele "Bob just used
   `canonical' in the canonical way."

   Of course, canonicality depends on context, but it is implicitly
   defined as the way *hackers* normally expect things to be.
   Thus, a hacker may claim with a straight face that `according to
   religious law' is *not* the canonical meaning of
   `canonical'.