For upload campaigns with a more restricted scope, it might be interesting to have several optional set of categories to pick from, e.g. for Monuments one could define:
(1) a list of monuments
(2) a list of types of views
for users to pick from. This would avoid them having to know the exact name of the category.
Ideally there would 4-5 such fields that allow to define lists of categories. As a delimiter of entries within the field, one could use "|". Displayed would be as a HotCat generated list of sub- or parent categories.