When working with geographical data, users often have low-level information such as postcodes, that they want to aggregate up to a larger region that there is no specific shapefile for. In these cases, it should be possible to provide a recode to the geographical map visualization that combines the lower-level categories into larger level categories, e.g., all postcodes between 1 and 100 belong to region A, 101 to 200 to region B, etc. When using that aggregated information in the map, we have a new set of regions, effectively, that the map should work with in the same way as usual.