It's used automatically as you move through hunks, see
diff-auto-refine. It is bound to `C-c C-b'.
-*** diff-create-changelog iterates through the diff buffer and tries
-to create ChangeLog entries for each change.
+*** diff-add-change-log-entries-other-window iterates through the diff
+buffer and tries to create ChangeLog entries for each change.
+It is bound to `C-x 4 A'.
** archive-mode has basic support to browse Rar archives.