+ 'git cat-file': "git cat-file blob v1.3.3:refs.c".
+
+. at-open-brace `@{` is used as a notation to access a reflog entry.
+
+With the `--print` option, if 'refname' is acceptable, it prints the
+canonicalized name of a hypothetical reference with that name. That is,
+it prints 'refname' with any extra `/` characters removed.
+
+With the `--branch` option, it expands the ``previous branch syntax''
+`@{-n}`. For example, `@{-1}` is a way to refer the last branch you
+were on. This option should be used by porcelains to accept this
+syntax anywhere a branch name is expected, so they can act as if you
+typed the branch name.
+
+EXAMPLES
+--------
+
+* Print the name of the previous branch:
++
+------------
+$ git check-ref-format --branch @{-1}
+------------