<?xml declaration

Chris Maden crism at ora.com
Mon Dec 15 15:44:23 GMT 1997

[Richard Light]
> 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.

Absolutely.  Note the disappearance of the "match/exactly match"
dichotomy from the terminology section of the specification; *all*
matches must be exact.

> Is there a particular reason for this?

It was a posted WG decision to use lower-case for all possible

> Other PIs will have a PItarget where 'xml' sits, and this isn't
> constrained to be any particular case.

Which ones?  The WG-produced specifications will use lower-case, and
other applications are forbidden from using [Xx][Mm][Ll] per the prose
in the section on names.

> Wouldn't it be kinder to make it '<?' ('XML'|'xml') ... ?!

Not really.  It was introduce an instance of case-insensitivity into
an otherwise completely case-sensitive specification, making education
more difficult.

> (The DTD declarations (<!ELEMENT, etc.) remain in upper case,
> presumably for compatibility with what SGML systems produce.)

Not for compatibility - it's required by ISO 8879.  The NAMECASE
GENERAL NO parameter in the SGML declaration only affects processing
of the DTD and document instance; keywords declared in the declaration
itself are still folded to upper case.  This means that any such
keywords (like ELEMENT, DOCTYPE, ATTLIST, NOTATION) must be uppercase.

<!ENTITY crism PUBLIC "-//O'Reilly//NONSGML Christopher R. Maden//EN"
"<URL>http://www.oreilly.com/people/staff/crism/ <TEL>+1.617.499.7487
<USMAIL>90 Sherman Street, Cambridge, MA 02140 USA" NDATA SGML.Geek>

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)

More information about the Xml-dev mailing list