I stumbled upon a problem when i tried to something like this
<root>
<ele type="a">
<atr1>first</atr1>
</ele>
<ele type="b">
<atr2>first</atr2>
</ele>
</root>
when i was trying to enforce that givven element can only have respective child elements if their attribute is set to respective values, that is inthis case, if it has "a", it can't have child .
But i can't really figure out how to do this in xml 1.0