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

class LTXMLLIB_API CNamespaceAliasMap
{
public:
CNamespaceAliasMap();

void Add(LPCTSTR lpctAlias, LPCTSTR lpctNamespace);
void RemoveNamespace (LPCTSTR lpctNamespace);

std::tstring GetNamespaceFromAlias (LPCTSTR lpctAlias) const;
std::tstring GetAliasFromNamespace (LPCTSTR lpctNamespace) const;
bool DoesNamespaceExist (LPCTSTR lpctNamespace) const;
bool DoesAliasExist (LPCTSTR lpctAlias) const;

int GetNamespaceCount () const;
std::tstring GetNamespaceAt (int index) const;

};