I'm not talking about control. I'm talking about cooperation. If someone is spitting out stuff that they think is XML, or advertised as XML, then it should be XML. Inform the folks generating the data that they need to do some work. That way, you're not trying to error-correct for them, which each consumer will have to do separately. Down That Path Lie Monsters and Madness, and is the very reason that nothing is XML until it is XML, unlike the HTML tag soup we had before it.