Ornamental metal (wrought iron) fences are one of the most varied types of fences. They can have various combinations of pickets, rails, and all sorts of different ornamentation. As such, this ornamental fence family is the most complex of the 3 fences families posted thus far, though it is still rather basic.
There are 2 types that are built into this family: a 4′ tall fence with 3 rails and a finial top, and a 6′ tall fence with only 2 rails. In plan, it has a basic line-based symbol, with posts that update graphically. Like the previous 2 fences, the Length and visibility of the Left and Right posts are instance parameters.
There are quite a few type parameters controlling the rails, pickets, and posts. The post height is controlled by Height, with the pickets having an offset from both the bottom and the top of the overall height (Picket Base Offset, Picket Top Offset). Also, the Picket Spacing is the clear space (gap) between pickets.
Many of these can be seen in the Front Elevation of the family, if you want to understand them better. And though it may seem like a lot of parameters, they are necessary if you want to create varied types within the same family. Cheers!