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 |