Global gitignore is for idiosyncrasies of your computer, not for repo-specific stuff. For example if you use an editor that writes in-place backup or swap files (like .swp files with Vim’s default settings), or you’re on a Mac which writes .DS_Store files into every directory, you’re going to want those ignored for every repo. That way you can comfortably work with other people’s repos, even if they’re not configured for your particular setup.
The global ignore combines with gitignore files in each repo. So if it’s an ignore pattern that everyone working with that repo should have, put it in the repo.





Gitignore settings don’t prevent checking in run configs if that’s what you want to do. Even if someone has the run configs pattern ignored, they’ll get those files with the repo clone. Gitignore only prevents adding files that aren’t already checked in - it’s a guard rail to prevent accidentally checking in so something you don’t want. You can override ignore settings to check in something new in with
git add --force <filename>