Design Patterns in NVDL script

I am convinced that design patterns will emerge for NVDL. The only one that springs to mind is Start with X pattern. Using modes, if you insist that the instance should start in xyz namespace, (or abc namespace), then put these two in a mode tag, each in a namespace element. That way the instance must start with one of those two namespaces.

The only other one I have in mind is the use of useMode for for nested validation... but I'm unsure how this will work out. Please let me know if you have ideas