Push all notes:
git push <remote> refs/notes/*
Fetch all notes:
git fetch origin refs/notes/*:refs/notes/*
[[git-scm.org] (archive)]
A word of warning: do not use git pull in place of git fetch (that is, git pull origin refs/notes/*:refs/notes/* is wrong). The overall details are complex, but the particular reason git pull is wrong here is that you do not want to merge or rebase refs/notes/commits with your current branch.