The same as you create documents that don’t use XML namespaces. If you’re currently using Notepad on Windows or emacs on Linux, you can continue using Notepad or emacs. If you’re using an XML editor that is not namespace-aware, you can also continue to use that, as qualified names are legal names in XML documents and xmlns attributes are legal attributes. And if you’re using an XML editor that is namespace-aware, it will probably provide features such as automatically declaring XML namespaces and keeping track of prefixes and the default XML namespace for you.


Can I Use Qualified Names In Dtds?

Yes.
For example, the following is legal:

google:C CDATA #IMPLIED>

However, because XML namespace declarations do not apply to DTDs , qualified names in the DTD cannot be converted to universal names.
As a result, qualified names in the DTD have no special meaning.
For example, google:A is just google:A — it is not A in the XML namespace to which the prefix google is mapped.
The reason qualified names are allowed in the DTD is so that validation will continue to work.


Do Xml Namespace Declarations Apply To Dtds?

No.
In particular, an xmlns attribute declared in the DTD with a default is not an XML namespace declaration for the DTD.. (Note that an earlier version of MSXML (the parser used by Internet Explorer) did use such declarations as XML namespace declarations, but that this was removed in MSXML 4.


Does The Scope Of An Xml Namespace Declaration Ever Include The Dtd?


No.
XML namespaces can be declared only on elements and their scope consists only of those elements and their descendants. Thus, the scope can never include the DTD.


How Can I Declare Xml Namespaces So That All Elements And Attributes Are In Their Scope?


XML namespace declarations that are made on the root element are in scope for all elements and attributes in the document. This means that an easy way to declare XML namespaces is to declare them only on the root element.   _{Your Comment}