Re: <?xml declaration

Peter Murray-Rust (peter@ursus.demon.co.uk)
Thu, 11 Dec 1997 00:15:35


At 22:26 10/12/97 +0000, Richard Light wrote:
>
>Hi,
>
>I notice that the current draft has switched the case of the XML
>declaration and its arguments to lower case:
>
><?xml version="1.0" encoding="UTF-8"?>
>
>Now that case is significant, this presumably matters. Is there a
>particular reason for this? Other PIs will have a PItarget where 'xml'
>sits, and this isn't constrained to be any particular case. Wouldn't it
>be kinder to make it '<?' ('XML'|'xml') ... ?!
>
>(The DTD declarations (<!ELEMENT, etc.) remain in upper case, presumably
>for compatibility with what SGML systems produce.)

Maybe WG members authorised to speak about this will answer the 'why'
questions :-)

The main problems now facing XML-DEV'ers are:
- to remember what the various cases are in the XML spec. Of course the
parsers will remind us ungently :-) [These are Draconian bomb-out errors
unless I am mistaken :-)]
- to remember what the case sensitivity is in *other peoples* DTDs and
documents.

The second promises to be a real problem. (BTW I support the WG's motives
in introducing case sensitivity). I don't know whether we can help
ameliorate it here. This sort of thing:

[bringgg, bringgg]. "Hi Sue, my XML document has bombed out with 'unknown
element FOOBAR'."
"Mary, did you remember the capitals?"
"yes, I put them all in!"
"How many?"
"The whole lot."
"What? Two?"
"No, all SIX".
"Ah, you should only have two."
"Where?"
"The F and the B."
"Oh, well HTML is all caps".
"Yes, but this isn't HTML."
"Well it's a sort of extended HTML, isn't it?."
... and so on ...

I have no idea how to construct CML cases at present. If I follow the XML
spec I get all-lower-case-with-dashes-between-words. OK, except that -'- is
not a very friendly character for forming java names from. If I follow the
WC namespace proposal I get random upper and lower case for namespaces and
for elements. If I follow the RDF I get consistent namespace case and some
capitalisation in names.

So:
PLEA TO W3C
Please, it would help us a lot if at least the W3C could use a consistent
case style in their public-facing documents. At the moment it suggests they
haven't addressed this problem. [I don't believe they don't care.]

If this happened, at least some of the rest of us can follow W3C style.

I doubt we can convince the whole world to use one style, but languages
like Java and C++ do quite a good job of gently persuading people to use a
communal approach. XML/W3 could do, if they address it.

P.

Peter Murray-Rust, Director Virtual School of Molecular Sciences, domestic
net connection
VSMS http://www.nottingham.ac.uk/vsms, Virtual Hyperglossary
http://www.venus.co.uk/vhg