Mostly for internal parser use
Occasionally useful for tasks like finding out whether a document contains any XLinks
The NamespaceSupport class: 
package org.xml.sax.helpers;
public class NamespaceSupport {
  public final static String XMLNS = "http://www.w3.org/XML/1998/namespace";
  public NamespaceSupport();
  public void reset();
  public void pushContext();
  public void popContext();
  public boolean declarePrefix(String prefix, String uri);
  public String getURI(String prefix);
  public Enumeration getPrefixes();
  public Enumeration getDeclaredPrefixes();
  public String[] processName(String rawName, String[] parts, 
   boolean isAttribute);
   
}