[Deradon]

Another comment already mentioned the `.git/info/exclude` directory. For completeness link to the online docs: https://git-scm.com/docs/gitignore

git will take 3 files into consideration for "ignoring" files:

> $XDG_CONFIG_HOME/git/ignore, $GIT_DIR/info/exclude, .gitignore

How I use them:

* ~/.gitignore: stuff I want to ignore everywhere (`/myNotes`, `.DS_STORE`, ...)

* <project>/.gitignore: stuff that should be ignore for this projects and shared with others

* <project>/.git/info/exclude; stuff for this project that only I want to ignore

** this is also super useful in combination with `git-bisect`