There are special use cases when it is necessary to map a Revit instance to a dRofus Item. Materials and Drafting Views are these particular use cases.
Materials
When a material is added to a Revit family and the family is saved to dRofus, we can carry the Material with the Family. While While a family is loaded into a model, the material is also loaded into the material library.
If a Revit material is added to a Revit family, the material it can travel with it. When an item with a saved Revit family (with a material) is loaded into a model, the material is added to the project.
...
Drafting Views
Drafting views are instances of 2D drafted views in Revit models, but are not treated as occurrences in dRofus like all other instances. In this case, the View is treated like all other family types.
...