This hook is meant primarily for notification, and cannot affect
the outcome of `git-commit`.
+post-checkout
+-----------
+
+This hook is invoked when a `git-checkout` is run after having updated the
+worktree. The hook is given three parameters: the ref of the previous HEAD,
+the ref of the new HEAD (which may or may not have changed), and a flag
+indicating whether the checkout was a branch checkout (changing branches,
+flag=1) or a file checkout (retrieving a file from the index, flag=0).
+This hook cannot affect the outcome of `git-checkout`.
+
+This hook can be used to perform repository validity checks, auto-display
+differences from the previous HEAD if different, or set working dir metadata
+properties.
+
post-merge
-----------