need for template rules to specify namespace?

is it really necessary for a rule to require a namespace even thought the 
template builder does not expect them?

    <treecell label="rdf:mytitle" />
    <treecell label="rdf:mydescription/>

yet it appears that using a rule requires introducing an unnecessary 
namespace for the datasources

eg  rule for  mytitle = mozilla

    <rule namespace:mytitle="mozilla" />

is this true and if so couldnt  it be simplified allowing a null namespace ?

    <rule null:mytitle="mozilla" />