I have seen questions closed because they constitute "trivia". I believe that sometimes this is offered as an option when voting to close or delete. (Perhaps I am mistaken...)
For example: Strange jeep-hold cable used during Operation Horev - a popular question which I enjoyed answering. But why isn't it trivia? Who cares about one strange protuberance from one jeep in a relatively obscure military campaign that never actually achieved its objective?
I suppose the answer is that anything related to military gear deployed in the field is good History, and I can understand that.
Still, I'd like some more guidelines regarding what's trivial and what's not.