It could be a family doing a family history. I'll pull an example totally out of my head. Let's say the family of a chaplain in a prison received a letter from the head of that prison because that chaplain was killed during a prison riot in the 1800s. Well, that letter is still under perpetual protection because it was never published, but the family wants to write a family history and needs to publish it. Why shouldn't that letter be included in the materials that we can digitize anyway, if we are looking at prison riots and want to prepare documentation on our websites about that? There's no reason that material should not be included.
On May 31st, 2018. See this statement in context.