+
This is currently the default, but Git 2.0 will change the default
to `simple`.
-* `upstream` - push the current branch to its upstream branch.
+* `upstream` - push the current branch to its upstream branch
+ (`tracking` is a deprecated synonym for this).
With this, `git push` will update the same remote ref as the one which
is merged by `git pull`, making `push` and `pull` symmetrical.
See "branch.<name>.merge" for how to configure the upstream branch.