I want to make release notes by using git notes, but I am not sure if other people change my git notes by using the same ref.
BTW, chmod 444 .git/refs/notes/abc_test
& .git/logs/refs/notes/abc_test
does not work.
I don't think you really can protect published git notes.
What you can do is put them in an explicit namespace, as mentioned in here:
I think for "typical usage" one stores others' notes in a different place anyways, e.g. I store Thomas' list-notes in refs/remotes/trast/notes/ so that they don't interfer with my own notes.
If in the same namespace, then they can be merged:
git checkout refs/notes/commits
git fetch origin refs/notes/commits
git merge FETCH_HEAD
git update-ref refs/notes/commits HEAD
git checkout master
But that would change their content.