So back with HRD 6.7xxx you enabled a new call lookup method called Unique CallSign Database that I'm still trying to figure out what it's good for, or if it actually even works. You state in the online documentation that the public list is updated by you guys at HRD and downloaded with the country list. You also state that Operators can create and maintain their own private list, but I've never seen any documentation on how to do so. So what's the deal with the UCSDB, is it functional or not?
So I did a bit more digging, and it appears that the UCSDB is loaded and accessed through the Countries manager. If you select the "Uniques" button, it allows you to select either the Public List (maintained by HRD), or the Private List (maintained by you). In the Private list, I added 4U75UN which is a call being used by the United Nations as a special event call now. Seems that the public list hasn't been updated in awhile, as the last update I have was in February of this year. But that seems like it's going to be a difficult list to keep accurate especially now with many operations canceling their plans at the last minute due to Covid restrictions.