If you have a file named "MyFile.txt" and another system is looking for "myfile.txt", then it'll not be found and Apple will not let you rename it because it thinks it's a no-op. That's frustrating as hell.
> The default is false, except git-clone(1) or git-init(1) will probe and set core.ignoreCase true if appropriate when the repository is created.
https://www.kernel.org/pub/software/scm/git/docs/git-config....