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Re: DTD and Schema Teasers

• To: "'xml-dev@l...'" <xml-dev@l...>
• Subject: Re: DTD and Schema Teasers
• From: "G. Ken Holman" <gkholman@C...>
• Date: Wed, 17 Dec 2003 10:33:10 -0500
• In-reply-to: <15725CF6AFE2F34DB8A5B4770B7334EE03F9F08B@h...>

At 2003-12-17 08:38 -0600, Bullard, Claude L (Len) wrote:
>Two only slightly related questions:
>
>1.  Why did XML keep the requirement for deterministic models?

XML DTDs kept deterministic models, probably because of compatibility with 
SGML ... XML markup doesn't have a requirement for deterministic models ... 
I sure like that RELAX-NG doesn't require this.

Actually, it even says why for DTDs explicitly in the spec:

   http://www.w3.org/TR/REC-xml#determinism

>2.  What are good reasons for having multiple schemas for the same
>     instance?

Document life-cycle ... at different stages of a document's life there may 
be different sets of validation requirements.

Document audience ... what one person needs might be poison to another.

Document processing ... one can short-circuit coding in a program by 
delegating certain tasks to validation.

Probably lots of others as well ....... keeping any reference to a document 
model out of the document itself is, in my opinion, a Good Thing.

In summary: how one looks at a document should be up to the recipient, I 
think, more so than the sender.

I hope this helps.

............... Ken


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• References:
  • DTD and Schema Teasers
    • From: "Bullard, Claude L (Len)" <clbullar@i...>

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