this seems to be pointlessly nested
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index 26ddd8f..9828662 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -785,17 +785,14 @@
inherits :class:`codecs.IncrementalDecoder`.
-Advanced topics
----------------
-
-Here we will discuss several advanced topics pertaining to the concrete
-I/O implementations described above.
-
Performance
-^^^^^^^^^^^
+-----------
+
+This section discusses the performance of the provided concrete IO
+implementations.
Binary I/O
-""""""""""
+^^^^^^^^^^
By reading and writing only large chunks of data even when the user asks
for a single byte, buffered I/O is designed to hide any inefficiency in
@@ -808,7 +805,7 @@
use buffered I/O rather than unbuffered I/O.
Text I/O
-""""""""
+^^^^^^^^
Text I/O over a binary storage (such as a file) is significantly slower than
binary I/O over the same storage, because it implies conversions from