That would be one easy way to get the information in, although in the case where no name is given it may seem a little odd no have an empty universe element. If we’re going to change up the XML, it might make more sense to just group cells logically under a <universe> element, i.e., something like
<universe id="1" name="My universe">
<cell id="1" ... />
<cell id="2" ... />
<cell id="3" ... />
</universe>
<universe id="2" name="Your universe">
<cell id="4" ... />
<cell id="5" ... />
<cell id="6" ... />
</universe>