Currently we have a bloated backlog, which ideally I want to move non-essential stories/tasks to a holding tank to make the backlog easier to read and administer. I've created a new board "holding-tank", which has duplicated our current backlog, and then as an experiment deleted a single task from the backlog to see if it's still apparent on the newly created holding-tank board. Unfortunately the deletion has actually removed it from both boards! Is there a way to prevent this from occurring please? If not, is there another method of creation to gain the same result please?