I used to work for a company where the American devs indented with 4 spaces, and the German devs indented with 2 spaces. When they finally decided to standardize the code style across the company, they couldn't agree on indentation. So, they compromised and everyone started indenting with 3 spaces. I swear I'm not making this up. I worked on one codebase that lived through that transition, and some source files would have all 3 indentation styles scattered throughout.