Georeference datum
I see that Georeference datum in the Add method form is a free text field: I wonder if it might not be a good idea to transform it into a controlled vocabulary. Not necessarily a key/value lookup table, but at least provide a finite list of choices to the user. This is because if we want to select all WGS-84 coordinates we might get "WGS", "84", "WGS84" and not be able to group similar coordinates.
This might not be a priority, since the majority of coordinates are provided in the WGS-84 standard, but there are regions that use other datums by default.