This may be a little trivial, but I was always curious about the numbers suffixed to the URL's for the forums.
like,
https://forums.macrumors.com/forums/ios-12.204/
https://forums.macrumors.com/forums/macos-high-sierra-10-13.203/
https://forums.macrumors.com/forums/iphone.99/
etc. do those...