[EXI] NS event encoding for default namespace

Hi EXI WG
        Should the NS event be encoded for default namespace also.
 
Assume the below XML document
 
<root xmlns="www.urn.foo">
</root>
 
Is the following sequence correct ?
 
SD 
SE(root) 
NS uri="www.urn.foo" prefix=""
EE
ED
 
I dont feel any use of the NS event here as it is a default namespace case.
Please clarify.
 
 
regards
Santhanakrishnan