error in namespace recommendation?

I'm not sure if this is an error but this namespace constraint

Namespace Constraint: Leading "XML"
Prefixes beginning with the three-letter sequence x, m, l, in any case
combination, are reserved for use by XML and XML-related specifications.

seems to imply that the namespace xmlns is allowed , ie I could have
<test xmlns:xmlns="some URI">

But this namespace constriant

Namespace Constraint: Prefix Declared
The namespace prefix, unless it is xml or xmlns, must have been declared
in a namespace declaration attribute in either the start-tag of the
element where the
prefix is used or in an an ancestor element (i.e. an element in whose
content the prefixed markup occurs). The prefix xml is by definition
bound to the namespace
name http://www.w3.org/XML/1998/namespace. The prefix xmlns is used only
for namespace bindings and is not itself bound to any namespace name.

seems to imply that the xmlns namespace is predefined.  If that's the
case shouldn't the first namespace constraint prohibit a leading xmlns?

Thanks.

Received on Tuesday, 4 July 2000 13:14:00 UTC