Document the newly added codec
diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index c58505a..5b30682 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -897,6 +897,8 @@
 | cp500           | EBCDIC-CP-BE, EBCDIC-CP-CH,    | Western Europe                 |
 |                 | IBM500                         |                                |
 +-----------------+--------------------------------+--------------------------------+
+| cp720           |                                | Arabic                         |
++-----------------+--------------------------------+--------------------------------+
 | cp737           |                                | Greek                          |
 +-----------------+--------------------------------+--------------------------------+
 | cp775           | IBM775                         | Baltic languages               |