[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Namespace question

• From: Peter Murray-Rust <peter@u...>
• To: xml-dev@x...
• Date: Fri, 07 Apr 2000 09:34:14 +0100

At 09:43 PM 4/6/00 -0600, Linda Grimaldi wrote:
>Am fairly new to this mailing list, and I must admit, the sheer volume and 
>intensity of the messages is very impressive.  I'm looking forward to 
>participating more actively.  But, for the moment, I hope you have patience 
>for a relatively newbie question, to wit;   How would I go about 
>registering an XML namespace designation?  Is it an IANA thing?
>
Greetings, Linda,

	We welcome new participants and this is an important question. A namespace
is a syntactic mechanism for uniquifying names in an XML document, and the
uniqueness is guaranteed by the requirement to map onto a URI. Anyone can,
in principle, use any combination of URIs in their document to uniquify
names. There is no requirement that the URI be associated with a real
resource.

	Namespaces anticipate that the document might be re-used in conjunction
with  other XML documents and therefore it is prudent to use URIs over
which you have control or are associated with. If everyone does this then
we can be sure that there will be no collisions. I suspect that the use of
URIs which do not represent the intention of the URI owner will be
deprecated (and might even infringe intellectual property rights), but it
is not forbidden in XML - there is no concept of a URI owner. (We have had
much debate about this).

	In practice I suspect that most namespaces will be associated with DTDs or
schemas. Thus if you wish to my Chemical Markup Language (CML ) DTD (or
schema, being published shortly) it is conventional to use
http://www.xml-cml.org. This is unique and the intention is that everyone
uses it to avoid collisions with, say, HTML, MathML, and the thousands of
other DTDs/Schemas. 

You and anyone else are welcome to use "cml" as a namespace prefix, e.g.:

<cml:blockquote
xmlns:cml="http://www.w3.org/TR/REC-html40-971218/loose.dtd">...
  <html:molecule xmlns:html="http://www.xml-cml.org">

This might be perverse for human readers but the prefixes have no semantics.

There is (I believe) nothing to stop you from using
"http://www.xml-cml.org" for something other than CML.*I* would get very
upset but XML itself would not give me redress. 

OASIS (http://www.oasis-open.org) acts to provide a repository for DTDs and
schemas, and I intend that CML is officially in this repository. I am not
sure that this gives it any legal status, nor that it stops anyone using
"http://www.xml-cml.org" either accidentally or maliciously. You may find
an OASIS member takes up this point. Beyond that I don't think we have any
more formal body. 

	P.




***************************************************************************
This is xml-dev, the mailing list for XML developers.
To unsubscribe, mailto:majordomo@x...&BODY=unsubscribe%20xml-dev
List archives are available at http://xml.org/archives/xml-dev/
***************************************************************************

• References:
  • Namespace question
    • From: Linda Grimaldi <grimlinda@e...>

• Prev by Date: Re: DTDs/Schemata for dictionaries?
• Next by Date: Re: Parser Behaviour (serious)
• Previous by thread: Namespace question
• Next by thread: Re: Namespace question
• Index(es):
  • Date
  • Thread