John Cowan cowan at
Thu Jun 25 21:40:21 BST 1998

Simon St.Laurent wrote:

> I'm also not completely sure about the use of href in the system identifier.
> Is it appropriate?  If it refers to a helper application, it seems like a bad
> idea.

HREF is an abbreviation for hyper-reference, and to me only suggests
that the attribute value is an URI, not what it is for.  So I say keep it.
> I'm one of those strange people who actually _likes_ MIME types and
> HTTP's odd habit of identifying the content it delivers and expecting
> applications to cope.

Perhaps there should be a convention mapping MIME types onto XML
notation names.  Of course, the "/" in MIME types isn't an XML
name character, so it would have to be mapped into something else.

Unfortunately, there is just one ASCII character not already permitted
in MIME types that is allowed in XML names.  Colon.  Which is
gonna be used for something else.  @*#$.

If all documents were in UTF-8, that wouldn't be a problem: choose
a non-ASCII name character.  But they aren't, and NCRs aren't
allowed in names.  Lose, lose.

> But hey, I could start using my ISBNs - or are those the
> property of my publisher?  Hmmm.  Time to read the contracts.

AFAIK using an ISBN -- and, a fortiori, the urn:isbn:* URIspace,
is open to anyone.  (It's not even very hard to get your own
portion of the ISBN space if you publish your own books.)
After all, people cite books by ISBN, and a hyperlink is just another
kind of citation.

> 2.5 Notation Declarations
> Notation declarations are made with XSC:Notation elements nested in the
> XSC:XSchema element.
> <!ELEMENT XSC:Notation (Doc?, ((PubidLiteral, SystemLiteral?) |
> SystemLiteral))>
> <!ATTLIST XSC:Notation
>       name NMTOKEN #REQUIRED>
> <!ELEMENT XSC:PubidLiteral EMPTY>
> <!ATTLIST XSC:PubidLiteral
>         Pubid CDATA #REQUIRED>
> <!ELEMENT XSC:SystemLiteral EMPTY>
> <!ATTLIST XSC:Systemliteral
>         href CDATA #REQUIRED>
> Notations may include either a Public Identifier and an optional system
> literal, or just a system literal.

Confusing way to put it.  Notations may include a pubid or a sysid
or both in that order.  The formal content model is phrased the way
it is -- Ron's draft used

        (PubidLiteral | SystemLiteral | (PubidLiteral, SystemLiteral))

-- just to avoid SGML ambiguity.

My original draft used attributes directly on the
Notation element here, and left it #IMPLIED (:-)) that a Notation
element with neither pubid nor sysid was bogus.

I'd like to put it back that way for simplicity's sake. The above
mechanism (Ron's) is correct but over-complicated, IMHO.

John Cowan		cowan at
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)

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