Are the names of all element types and attributes in some XML namespace

Are the names of all element types and attributes in some XML namespace?

Answer:

No.
If an element type or attribute name is not specifically declared to be in an XML
namespace -- that is, it is unprefixed and (in the case of element type names) there is no
default XML namespace -- then that name is not in any XML namespace. If you want,
you can think of it as having a null URI as its name, although no "null" XML namespace
actually exists. For example, in the following, the element type name B and the attribute
names C and E are not in any XML namespace:
<google:A xmlns:google="http://www.google.org/">
<B C="bar"/>
<google:D E="bar"/>
</google:A>

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