Between raw and cooked II: Are? DTDs are just for validation

Didier PH Martin martind at
Thu Apr 1 17:59:22 BST 1999

HI Jonathan,

    If DTDs *were* only for validation there would be no issue here. However
DTDs provide additional functionality beyond validation, namely default
attributes and entities. The problem exists in that XML parsers can *choose*
whether or not to validate and in so doing the <em>information content</em>
of the XML document is altered.

    Validation is optional. Says so. Given this, the question becomes: ought
parsers be allowed to expand entities and default attributes with validation
turned off? What problem does this create?

    Perhaps the XML spec should properly specify that:

         *if* a DOCTYPE declaration is present which specifies a DTD then
the document must be validated else the parser must generate an error.
(DOCTYPE declarations would remain optional).

    In this way document authors would be able to properly specify
information content.

Thanks for bringing back the issue at its source: the spec. According to the
spec nothing is said about how to interpret a document. It just say how a
document is to formatted but not how it is to be interpreted. Now that real
stuff is going out we see that holes are in the architecture. The holes
being: what do we do with this? this question is dependent on type of
interpreters like:
a) browsers
b) ERP front ends and back ends
c) repositories
d) any other stuff I am not think of right now

there is no specs on how you do interpret or parse a document in the context
of a browser. Your suggestion is a constructive one. You propose that the
next spec version reduces the ambiguity on the parsing stage by including in
the specs the parsing rule. the specs should also reduces the ambiguity with
external references, so, to speak, to explicitly state if a parser should
consider the presence of a DTD as a signal to validate the document.
Actually it is leaved at the mercy of the implementer and no specifications
are available to dictate the rules of conduct.

Thanks Jonathan for a constructive comment. Any other constructive opinion?
I mean here, any suggestions concerning the rules or more specifically the

Didier PH Martin
mailto:martind at

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