Reserved names and documentation

[david at megginson.com]

Borden, Jonathan writes:

 > If this is indeed the case, as it appears to be, then namespaces
 > have no real meaning outside of the xxx: prefix. namespaces become
 > nothing more (or less :-) than a standard naming mechanism for
 > tags. the namespace referenced urn is nothing more than an
 > arbitrary statement of who is supposed to own the "xxx:" namespace
 > prefix.

Bingo!  Or, to express it more generally, namespaces provide a
convention for naming XML 1.0 elements and attributes in such a way
that the names are globally-recognisable and globally-unique.  This
may seem like a small victory, but it enables me to do two things:

1. I can write code for handling a certain element type in *any*
   document, rather than just in documents of a specific type.  If I
   know how to handle the element type

     http://www.w3.org/Profiles/voyager-strict a

   in HTML, then I know how to handle it in NITF as well.

2. I can allow other people to extend my document type without
   conflict, since their "name" element and my "name" element will be
   clearly distinguished.  

   (Of course, I still need to establish handling rules: if I find an
   element type that I do not recognise, do I throw an error, skip the
   element and its descendants, or skip the element and process its
   descendants?  In RDF, it's simple enough just to skip unknown
   properties, but in richer document types, that won't always work.)


All the best,


David

-- 
David Megginson                 david at megginson.com
           http://www.megginson.com/

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