In the “Class Specifiers” documentation (Class Specifiers | Unreal Engine Documentation), it is stated that HideCategories “Lists one or more categories that should be hidden in the Unreal Editor Property window for Objects of this class.”.
Now, it would be awesome if it was only affecting Property Windows, but that’s not how it works: it also makes the default values of the properties uneditable in the children and the functions not searchable in the graph - which is just plain horrible and renders this feature useless. Why would I want to hide a property category instead of setting the members to private? Probably most of us just want to hide the categories from the detail panels, as their default values of run-time variables make no sense.
Back on topic, is it a documentation error, or does it work incorrectly?