<p>
The naming rule allows you to control how to name the category groups. If left empty, 
the groups will be named after the regular expression match (equivalent to filling with just $1). 
But you can use any of the regex backreference markers to name your group. By default, 
at least one group ($1) will be available. If you use any other grouping parenthesis, 
those will be used as well.
</p>
<p> Examples:
<ul>
	<li>"Group $1" : the group names will have a leading "Group "</li>
	<li>"$1 something" : the group names will be suffixed with " something"</li>
	<li>"An specific label" : the group name will be "An specific label"</li>
</ul>
</p>