Index: Doc/reference/lexical_analysis.rst
===================================================================
--- Doc/reference/lexical_analysis.rst	(revision 67036)
+++ Doc/reference/lexical_analysis.rst	(working copy)
@@ -606,6 +606,7 @@
    single: floating point literal
    single: hexadecimal literal
    single: octal literal
+   single: binary literal
    single: decimal literal
    single: imaginary literal
    single: complex; literal
@@ -631,9 +632,11 @@
    longinteger: `integer` ("l" | "L")
    integer: `decimalinteger` | `octinteger` | `hexinteger`
    decimalinteger: `nonzerodigit` `digit`* | "0"
-   octinteger: "0" `octdigit`+
+   bininteger: "0" ("b" | "B") `bindigit`+
+   octinteger: "0" ("o" | "O") `octdigit`+ | "0" `octdigit`+
    hexinteger: "0" ("x" | "X") `hexdigit`+
    nonzerodigit: "1"..."9"
+   bindigit: "0" | "1"
    octdigit: "0"..."7"
    hexdigit: `digit` | "a"..."f" | "A"..."F"
 
Index: Doc/library/stdtypes.rst
===================================================================
--- Doc/library/stdtypes.rst	(revision 67036)
+++ Doc/library/stdtypes.rst	(working copy)
@@ -244,9 +244,11 @@
    pair: complex number; literals
    pair: hexadecimal; literals
    pair: octal; literals
+   pair: binary; literals
 
 Numbers are created by numeric literals or as the result of built-in functions
-and operators.  Unadorned integer literals (including hex and octal numbers)
+and operators.  Unadorned integer literals (including hexadecimal, octal and
+binary numbers)
 yield plain integers unless the value they denote is too large to be represented
 as a plain integer, in which case they yield a long integer.  Integer literals
 with an ``'L'`` or ``'l'`` suffix yield long integers (``'L'`` is preferred
Index: Doc/library/functions.rst
===================================================================
--- Doc/library/functions.rst	(revision 67036)
+++ Doc/library/functions.rst	(working copy)
@@ -112,6 +112,15 @@
    .. versionadded:: 2.3
 
 
+.. function:: bin(x)
+
+   Convert an integer number to a binary string. The result is a valid Python
+   expression.  If *x* is not a Python :class:`int` object, it has to define an
+   :meth:`__index__` method that returns an integer.
+
+   .. versionadded:: 2.6
+
+
 .. function:: bool([x])
 
    Convert a value to a Boolean, using the standard truth testing procedure.  If