It would have to be not only Hidden from any subscribers to the thread not staff, but not trigger notification or alerts.
Sometimes it's very useful to share a note with my staff on problems relating to a member. Would be good to have this on the problem thread itself.
I imagine the disabled notification or alerts would mean a mod.
I was thinkling a soft deleted post maybe but then it doesn't display the content.
Plus I'd still have the notification or alerts triggered by making the post originally before it is soft deleted.
Also HELP I soft deleted a post to see what happened and I can't see how to reinstate it. I clicked Show - is that enough to Undo the Soft Delete?