2.0cN, and *those* precede 2.0.
You may also find version numbers with a "+" suffix, e.g. "2.2+". These are
-unreleased versions, built directly from the Subversion trunk. In practice,
-after a final minor release is made, the Subversion trunk is incremented to the
-next minor version, which becomes the "a0" version,
-e.g. "2.4a0".
+unreleased versions, built directly from the CPython development repository. In
+practice, after a final minor release is made, the version is incremented to the
+next minor version, which becomes the "a0" version, e.g. "2.4a0".
See also the documentation for :data:`sys.version`, :data:`sys.hexversion`, and
:data:`sys.version_info`.