Re: Public ID for Dublin Core DTD

[John Cowan <cowan@mercury.ccil.org>]

Arnold, Curt scripsit:

> I've traded emails with one of the authors and he seems open to defining
> a public identifier for the DTD, but neither of us really know all the
> rules to do it right.  Public Identifiers seem to be a real backwater
> and it would be nice if it was addressed on http://www.w3.org/addressing
> or somewhere comparable.

*Public* identifiers can be any string you like, within the character
repertoire specified in XML 1.0.

I will assume you want to know about *formal* public identifiers (FPIs), the
kind used on the various HTML DTDs.  These are defined by ISO 8879 (SGML)
and ISO 9070 (FPI registration), not by W3C.

The general format of an FPI for a DTD is:

	-//owner//DTD title//lang

where "owner" is a fairly unique string denoting the owner (like "W3C" or
"Acme Technologies, Inc."), "title" is a string denoting this particular
DTD, and "lang" is an RFC 3066/ISO 639 code for the language in which
the DTD is written, typically "EN" for English.

There is supposed to be a registration mechanism for owner strings, but
it is broken for arcane political reasons, so the leading "-" denotes
"unregistered".  Don't worry about this.

The term "DTD" can be replaced by any of 13 other terms if you are
assigning an FPI to anything other than a DTD; for example "ENTITIES"
for a list of entity declarations.

You can segment  the owner or the title into subdivisions
(most important first/big-endian) using "::", thus:
"Company::Division::Department".

-- 
John Cowan                                   cowan@ccil.org
One art/there is/no less/no more/All things/to do/with sparks/galore
	--Douglas Hofstadter