If you use the "xml" keyword (in any combination of uppercase or lowercase letters) in
user-defined namespace prefixes in an XML document, the Microsoft XML (MSXML) parser generates the following error message:
The namespace prefix is not allowed to start with the reserved string "xml."
The xml keyword in any combination of uppercase or lowercase letters is a reserved word, and therefore cannot be specified as the first three characters of a user-defined namespace prefix.
Rename the namespace prefix so that it does not begin with the xml keyword.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.