space in root node

Hello,

I do not know if the root node (or any other node) can have a name with
a space. I assume not, although it is very hard to find it in on w3c
recommendations. 

With mlview it is possible to make a root node with a space in it.
If I create a new document with node name "Hello world" an save it, the
document is created with this node name. Afterwards if I open this saved
document, the program gives me a nice error message :

 /tmp/test.xml:2: parser error : Specification mandate value for
attribute world
<Hello world/>


regards,
Bart