Describe git checkout

diff --git a/pep-git.txt b/pep-git.txt
index 53e30d6788d807ce29a0f6ca028355276c195587..4cbedf62b90518b76f02adb2565cde2c7395e5df 100644 (file)
--- a/pep-git.txt
+++ b/pep-git.txt
@@ -381,7 +381,20 @@ or shared repository.
 Undo
 ====
 
-TODO: describe undo strategies: git reset, git revert, git checkout,
+Whatever you do, don't panic. Almost anything in git can be undone.
+``git checkout``, for example, can be used to restore the content of
+file(s) to that one of a commit. Like this::
+
+    git checkout HEAD~ README
+
+The commands restores the contente of README file to the last but one
+commit in the current branch. By default a commit ID is simple HEAD;
+i.e. ``git checkout README`` restores README to the latest commit.
+
+(Do not use ``git checkout`` to view a content of a file in a commit,
+use ``git cat-file -p``; e.g. ``git cat-file -p HEAD~:path/to/README``).
+
+TODO: describe undo strategies: git reset, git revert,
 git reflog. "Commit early, commit often".
 
 How to undo a merge