The Economist on Semantics

Paul Prescod (papresco@technologist.com)
Thu, 23 Apr 1998 22:35:23 -0400


"Whereas HTML has a set lexicon of about 90 tags, XML has an infinite one=
:
authors of XML documents can invent their own tags. The tag names, and
what they mean, are left for the author to define depending on the subjec=
t
matter.=20

This sounds splendid=97but it presents a problem for browsers such as
Netscape Navigator and Internet Explorer, which will need somehow to
interpret all of these new tags. Thus each XML document must be provided
with an appendix, known as the Document Type Definition (DTD), a kind of
glossary containing information on the nature of the document=92s content=
,
the tags used for various elements, as well as a listing of where in the
document the tags occur and how they fit together."

Now we know. All semantics go in the DTD.

http://www.economist.com/editorial/freeforall/current/index_st4501.html?s=
t.ne.fd.mnaw

Paul Prescod - http://itrc.uwaterloo.ca/~papresco

"Perpetually obsolescing and thus losing all data and programs every 10
years (the current pattern) is no way to run an information economy or
a civilization." - Stewart Brand, founder of the Whole Earth Catalog
http://www.wired.com/news/news/culture/story/10124.html