RE: [docbook-apps] what's the value of the document type declarat ion?

["Robert P. J. Day" <rpjday@mindspring.com>]

On Tue, 3 Jun 2003, Jeff Beal wrote:

> However, as I think about it a little bit more, the document below is a
> well-formed document using general entities, but not pulling in an external
> DTD (assuming that introduction.xml and chapter1.xml are both well-formed
> XML fragments):
> 
> <!DOCTYPE book [
>  <!ENTITY introduction SYSTEM "introduction.xml">
>  <!ENTITY chapter1 SYSTEM "chapter1.xml">
> ]>
> <book>
>  <title>A Non-validating document</title>
>  &introduction;
>  &chapter1;
> </book>
> 
> This won't validate, of course, because you haven't defined any elements,
> but an XML parser will still be able to find your document fragments.

i did check that out, but i was also trying to keep things relatively
mainstream, so i let that one go as being just a bit contrived.

so i'm adding to my little tutorial the functions of the document type
declaration:

1) for potential validation (non-essential for actual transformation)
2) for default attribute values defined in the DTD
3) for included entities
4) for the ability to define additional internal and external
   general entities

i think i'll leave out the ability to have internal DTD subsets --
that's just a bit much for now.  thanks.

rday