It’s great that BIBFRAME 2.0 supports carrier description information. Overall, it is well done and meets the needs of RDA cataloging.
There is, however, one area that could use improvement: digital representation of cartographic information. Different cataloging codes or encoding schemas record this information with different levels of granularity. RDA uses a single property (rule 3.19.8) that may contain three different types of information: data type, object type, and number of objects. BIBFRAME, on the other hand, uses three separate classes: CartographicDataType, CartographicObjectType, and ObjectCount.
The result is that is difficult to impossible to map this RDA property into BIBFRAME cleanly. This could be resolved by adding an intermediate level to the BF class hierarchy, e.g.
In this way, a code or schema at any level of granularity has a place for a mapping. That is, RDA could map to CartographicRepresentation, while MARC, which uses separate subfields, can map to the appropriate subclasses.
The class name “CartographicRepresentation” can, of course, be whatever you deem best.