PTC told me, that this functionality is not available in creo parametric 2.0 and I have to create here an idea. They mean, we should use a family table instead, but this is not what we want to use in our company. We don't want to create for a part two numbers in Windchill, because the part is used in a weld assembly and for us it is the same part with or without weld preperation like a chamfer. So, any idea to solve the problem, maybe with a different functionality ?