XML Syntax - NAMESPACE clause
The NAMESPACE clause sets or identifies the namespaces that are
contained in an XML document.
Format

Syntax Rules:
- Data-name-1 is an alphanumeric data item which contains the
namespace URI (Uniform Resource Identifier).
- Literal-1 is a fixed namespace URI.
- If the NAMESPACE clause appears on a group item's declaration,
then data-item-1 must be defined directly within that group item.