Jirka Kosek <> wrote on 02/11/2009 05:09:21 PM:
> wrote:
>
> > "When designing computer systems, one is often faced with a choice
between
> > using a more or less powerful language for publishing information, for
> > expressing constraints, or for solving some problem. This finding
explores
> > tradeoffs relating the choice of language to reusability of
information.
> > The 'Rule of Least Power' suggests choosing the least powerful
language
> > suitable for a given purpose."
>
> I think that my understanding of intent of authors of this document is
> very different from you. I don't think that this TAG finding is
> discouraging use of general extensibility mechanism. My understanding is
> that rule of least power prefers markup like:
>
> <p>foo</p>
>
> over
>
> <p>
> <r>
> <t>foo</t>
> </r>
> </p>
>
> You can find another TAG findings related to XML versioning and
> extensibility strategies:
>
> http://www.w3.org/2001/tag/doc/versioning-compatibility-
> strategies#dt-extensible
>
> http://www.w3.org/2001/tag/doc/versioning-xml
>
> So I don't think that picking up some arbitrary TAG finding is a good
> argument agains/in favour of general extensibility.
>
Levels of understanding will vary. I see this as being of broad
applicability. Certainly the practice of the W3C has not been one of
allowing generalized use of namespaced extensions in every standard. And
the argument that "XML allows extensibility, so every XML standard should
allow such extensibility" is silly. Certainly, ODF is also Unicode, and
Unicode has a mechanism for adding extensions. Should we then allow PUA
characters in ODF? ODF uses ZIP, and ZIP allows extension compression
algorithms. Should those then be allowed? The answer is obviously no, or
at least not obviously yes. The nature of standardization is making
choices, and it is not only respectable for an XML-based standard to
define a schema that disallows generalized XML extensions, it is the more
typical practice, in OASIS and in the W3C. I'm not saying that there are
not open content model standards out there, but that they are in the
distinct minority.
-Rob
