Renaming 'structured' and 'unstructered' domains.
In my opinion the wording of 'structured' and 'unstructured' domains is misleading. The 'unstructured' domains can have plenty of structure, too, e.g. a vector-field. Mathematically, 'structured' domains are manifolds and 'unstructured' domains are fibers/Fasern that are defined on top of the product of all manifolds. Together, everything forms a fiber-bundle.
See, for reference: https://en.wikipedia.org/wiki/Fiber_bundle