AliasNamespaceDictionary NamespaceAliases
 PropertyDescription 
  Property NameNamespaceAliases  
  Property Type string  
  Accessors Read Only  
  DescriptionA collection of name value pairs, containing a namespace URI and namespace Alias.  
  Remarks

These alias will be declared at the root level in the document.
The sample shows what you get if an alias “MyAlias”, and UIR "http://sample" are added to the collection.

<?xml version="1.0"?>
<MyAlias:Customer xmlns:MyAlias="http://sample"
xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
clubCardMember="false">

Also See CNamespaceAliasMap

public class AliasNamespaceDictionary : CollectionBase
{
    public String this[ String nsAlias ]
    {
        get ;
        set ;
    }
    public void Add( String nsAlias, String namespaceUri ) ;
    public bool Contains( String nsAlias ) ;
    public void Remove( String nsAlias ) ;
}