groves dissent

David Megginson david at
Tue Sep 28 03:36:29 BST 1999

Marc.McDonald at writes:

> It seems amazing that it is difficult to grasp that namespaces and
> aqrchitectures have little in common:

> 1. Namespaces handle ambiguity: the same name means different
>     things. <a> has more than one meaning hence <foo:a> and <bar:a>

> 2. Architectures handle synonyms: There are alternative names that
>    mean the same <a> really means <b> under architecture B and <c> 
>    under architecture C.
> There's a big difference between ambiguity and aliasing.

I think that you're overstating the difference, especially since AFs
also provide disambiguation.

The difference is one of degree, not of kind: AFs allow you to
associate more than one universal name with a single markup item,
while Namespaces allow you to associate only one universal name with a
markup item.  In other words

Namespaces:          markup-item (0,*) <-> name (0,1)
Architectural Forms: markup-item (0,*) <-> name (0,*)

Unfortunately, AFs came out with three strikes against them: they were
developed by ISO (yawn!), they were introduced as an appendix to the
very long and intense HyTime spec (awk!), and they weren't very webby
(oops!).  They also hit a foul with their convoluted mechanism for
attribute mapping.

I agree with Eliot Kimber and others, though, that eventually XML will
need something like AFs.

All the best,


David Megginson                 david at

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at
Archived as: and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo at the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at

More information about the Xml-dev mailing list