Question: How do you set up a unifier part?
Answer: Any part can easily be set to unify with itself by turning on the Section Unify Toggle and the setting the Section Unifier to "*Unify with Self*".
If you want to unify several parts together, concrete slabs and concrete beams, for instance, then you need to create a unifier part. Create a new part "*Concrete Unifier*" for instance, and then set this part as the Section Unifier for both Slabs and Beams.
Remember that the unifier part will not only unify slabs and beams, but will also set the drawing symboolgy for both the slabs and the beams.