It removes the first item, along with its trailing slash, from the string describing an inheritance path. In fact, although it's not obligatory to override all the tag methods at each step in the inheritance chain, SUIF does so, even in the abstract classes. To alleviate this, SUIF effectively initiates a new cascade at each new class. In fact, there is a new cascade at each new class for each of its superclasses. The result of this is that in existing SUIF classes, all the cascades are in place but none of them actually get used.
First cascade continues here.
3rd cascade starts here. 1st cascade continues here. At each level in every inheritance path, we initiate a new cascade for each of the parent classes. The local tag cascade is not layered with tributaries, but in the source code it is interwoven with the primary tag cascade. For this reason it is difficult to follow when browsing the code for the first time.