a valid head 'name'
(i.e. the contents of `$GIT_DIR/refs/heads/<head>`).
-<snap>::
- a valid snapshot 'name'
- (i.e. the contents of `$GIT_DIR/refs/snap/<snap>`).
-
File/Directory Structure
------------------------
Please see link:repository-layout.html[repository layout] document.
+Read link:hooks.html[hooks] for more details about each hook.
+
Higher level SCMs may provide and manage additional information in the
`$GIT_DIR`.