<?xml version="1.0"?> <!DOCTYPE doc [ <!ENTITY ent1 "<elem/>"> <!ENTITY ent2 "<ns:elem/>"> ]> <doc> <a xmlns="urn:a">&ent1;</a> <b xmlns="urn:b">&ent1;</b> <a xmlns:ns="urn:a">&ent2;</a> <b xmlns:ns="urn:b">&ent2;</b> </doc>