EventType.ValidateCommand includes Undo?

Here is the full documentation for EventType.ValidateCommand:

Validates a special command (e.g. copy & paste). "Copy", "Cut", "Paste", "Delete", "FrameSelected", "Duplicate", "SelectAll" and so on.

Does "and so on" include undo? I ask because all sample code I've found uses it to check for Undo (including an answer here: http://answers.unity3d.com/questions/33065/repaint-on-undo.html

However, in my own Editor code, the following does not catch an Undo event:

 if ( Event.current.type == EventType.ValidateCommand){
         Debug.Log("Event.current.type = " + Event.current.type);
 }

But this does:

 if ( Event.current.commandName == "UndoRedoPerformed"){
     Debug.Log("Event.current.commandName = " + Event.current.commandName);
 }

I can work with it using the 2nd method, but I'm worried why it isn't working, as there's zero documentation to explain.

Thanks