Like when you send a .7z instead of a .zip or .rar to a friend or a teacher because that’s what your computer has installed and they’re like “Oh No, not one of those, now I have to install 7Zip” even though the same program that opens .rar also opens .7z I feel like people are way more annoyed when they receive a .7z
I sometimes sent a .tar.gz and the teacher figured out how to open it. But he was a technical teacher for electronics. He still has nothing to do with Linux but I jist wanted to experiment.