diff -r 585ad5d806bd Doc/library/tarfile.rst
--- a/Doc/library/tarfile.rst	Fri Jun 06 17:43:37 2014 -0400
+++ b/Doc/library/tarfile.rst	Sat Jun 07 12:24:44 2014 -0700
@@ -81,6 +81,10 @@
    If *fileobj* is specified, it is used as an alternative to a :term:`file object`
    opened in binary mode for *name*. It is supposed to be at position 0.
 
+   For modes ``'w:gz'``, ``'r:gz'``, ``'w:bz2'``, ``'r:bz2'``, :func:`tarfile.open`
+   accepts the keyword argument *compresslevel* to specify the compression level of
+   the file.
+
    For special purposes, there is a second format for *mode*:
    ``'filemode|[compression]'``.  :func:`tarfile.open` will return a :class:`TarFile`
    object that processes its data as a stream of blocks.  No random seeking will