-PyDERASN depends on `six <https://pypi.org/project/six/>`__ package
-for keeping compatibility with Py27/Py35. It is included in the tarball.
-You can also find it mirrored on :ref:`download <download>` page.
-
-You could use pip (**no** OpenPGP authentication is performed!) with PyPI::
-
- $ cat > requirements.txt <<EOF
- pyderasn==5.5 --hash=sha256:TODO
- six==1.13.0 --hash=sha256:30f610279e8b2578cab6db20741130331735c781b56053c59c4076da27f06b66
- EOF
- $ pip install --requirement requirements.txt
+* ``termcolor`` is an optional dependency used for output colourizing.
+* ``urwid`` is an optional dependency used for :ref:`interactive browser <browser>`.
+* ``dateutil`` is an optional dependency used for ``.totzdatetime()`` method.