Currently if we want to restrict the visibility of banners to registered users meeting some conditions it has to be done using a javascript. I wonder if it'd be possible to have a built-in feature in CentralNotice for this so we don't have to build ad hoc JS inside the banners. I'd say that we look at some banners that had JS enabled to do this and see the most used options, so we could do that from the CentralNoticeBanners page, such as user has X edits (on this wiki - this set of wikis - all wikis) or user has registered Y time ago (on this wiki - this set of wikis - all wikis). Not sure how difficult could be though.