The Paragon people at some point decided that this way of working with formats was incomplete, and so a second level of hierarchy is included, Named Rulers. A ruler can be assigned a name; if this is done, a slightly different ruler icon appears, and the name can now be selected from a pop-up menu in the ruler at the top of the window as a way of assigning the given format to a paragraph, just as in Word. <more> Any changes made to the formatting of any paragraph governed by a Named ruler will instantly be applied to all paragraphs governed by a ruler with that name; this is what makes Named rulers so powerful and useful.
(If you've been working entirely with unnamed rulers and decide things would be easier if you used Named rulers instead, it is easy to make the transition: if you hold down Command as you name a ruler, all identical rulers throughout the document will be given that name. Try THAT with Microsoft Word! I'm deadly serious here: the only way in Word to give a single Style name to all identical paragraphs in Word is to find them all, one by one, and apply that style. Score a big one for Nisus here.)
Things can get a bit tricky in the interplay between named and unnamed rulers; you'll have to download the longer version of this review if you want details. <more>