--- a/doc/hg.1.txt
+++ b/doc/hg.1.txt
@@ -327,6 +327,16 @@ tip::
undo::
Undo the last commit or pull transaction.
+ Roll back the last pull or commit transaction on the
+ repository, restoring the project to its earlier state.
+
+ This command should be used with care. There is only one level of
+ undo and there is no redo.
+
+ This command is not intended for use on public repositories. Once
+ a change is visible for pull by other users, undoing it locally is
+ ineffective.
+
update [-m -C] [revision]::
Update the working directory to the specified revision.