As Manar's definition implies, a namespace has a rule set that
constrains the assignment of names within it and generally an Authority
that manages the namespace and the rules that govern it.
A namespace may be an enumerated list: that is a known, finite set of
permissable names, as we hope to achieve with formats and types.
Controlled vocabularies such as LCSH, MeSH, and the like are enumerated
lists of terms that populate their respective namespaces.
The names in a namespace need not be enumerated (and in fact, generally
are not)
ISBN constitutes a namespace comprised of the ISBNs issued and those
which could be issued according to the ISBN rules. The URL namespace is
an infinitely extensible naming domain, as is the DNS namespace.
Misha's post, which gave rise to this question, talks about namespaces
within XML:
> XML namespaces are used to assign unambiguous names to XML elements
> (including sub-elements) and attributes. In the following:
>
> <?XML:namespace href="http://purl.oclc.org/metadata/..." as="DC"?>
>
> we specify that "DC" stands for the schema defined at the
corresponding
> URL, so we know that to find the meaning of DC:Creator, we use that
URL,
> together with the string "Creator".
this convention provides the mechanism to reserve namespaces within the
markup scheme and to indicate a link to the authoritative definition of
the namespace.
Thus, the DC namespace is reserved in the above XML: declaration, and a
link to the authority for the namespace is provided:
http://purl.oclc.org/metadata/..."
So, everything specified according to the construct DC:<element-name> is
putatively part of the DC namespace, and some information about the
definition of a particular name could be found at the end of the link.
stu
On Friday, October 31, 1997 6:29 AM, Manar Hussain
[SMTP:[log in to unmask]] wrote:
> >For the benefit of some of the slower members of this list, would
> >someone define the term 'namespace' please?
>
> I'm probably not the most qualified to answer this but I'll give my
take on
> the term
>
> namespace: The set of names that can be validly used for a given
entity.
>
> Manar
>
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