Which clients support these types of reports?
For anyone who wants to check out the reports they are talking about: https://reports.slidestr.net/ for an overview of all reports.
Discussion
Damus, Amethyst, Coracle create the 1984 events with their report/block buttons.
Primal has their own internal table where they store reports and is not creating the events as far as I can tell.
What's more vague, is where they are used. Nostrudel displays them, Amethyst uses them apparently as well. Maybe some relays as well for spam?