One thing our wiki software does which is quite helpful is allow a user to share a page/resource with another registered user via its internal notification system. This allows people in moderation-like roles (not necessarily an official moderator) to draw attention to something requiring attention to someone who can provide some assistance.
Currently the only way to accomplish this is by @-mentioning someone. This may not be desirable especially if that person in the moderation-type role doesn’t have much to add.
Perhaps adding something to the share feature that would create a Message to a user pointing them to the topic? (And allow that sender to add a few words about why they should look?)