Issue #7631: Fix undefined references to the "built-in file object", which
has ceased to be.
diff --git a/Doc/library/filesys.rst b/Doc/library/filesys.rst
index b341f5f..31eaf0d 100644
--- a/Doc/library/filesys.rst
+++ b/Doc/library/filesys.rst
@@ -26,14 +26,13 @@
 
 .. seealso::
 
-   Section :ref:`bltin-file-objects`
-      A description of Python's built-in file objects.
-
    Module :mod:`os`
       Operating system interfaces, including functions to work with files at a lower
       level than the built-in file object.
 
    Module :mod:`io`
-      Python's framework for dealing with I/O including reading and writing
-      files.
+      Python's built-in I/O library, including both abstract classes and
+      some concrete classes such as file I/O.
 
+   Built-in function :func:`open`
+      The standard way to open files for reading and writing with Python.