diff -r 4a55b98314cd Doc/library/stdtypes.rst
--- a/Doc/library/stdtypes.rst	Mon Jan 12 21:03:41 2015 +0100
+++ b/Doc/library/stdtypes.rst	Mon Jan 12 15:16:34 2015 -0800
@@ -1332,6 +1332,30 @@
 :attr:`~range.stop` and :attr:`~range.step` attributes, for example
 ``range(0) == range(2, 1, 3)`` or ``range(0, 3, 2) == range(0, 4, 2)``.)
 
+Range objects are often inappropriate for non-integral types,
+especially inexact types such as :class:`float`.  In most cases, for
+such types, it is better to specify a count of numbers or intervals
+instead of a step size.  Care must be taken not to accumulate rounding
+errors, to avoid overflow and underflow, and to avoid using operations
+that unnecessarily restrict the types (e.g., if you only multiply and
+divide differences, the algorithm will work with
+:class:`datetime.datetime`; if you multiply and divide values
+themselves, it will not).  A simple version (a closed range, a count
+of numbers rather than intervals, potentially underflowing denormal
+values, and potentially being off by 1 digit on the :data:`stop`
+value) is:
+
+   >>> start, stop, num = 0, 10, 11
+   >>> step = (stop-start)/(num-1)
+   >>> [start + i*step for i in range(num)]
+   [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]
+
+.. seealso::
+
+   * `linspace recipe <http://code.activestate.com/recipes/579000/>`_
+     for an example lazy sequence built on this algorithm, and links
+     to alternatives.
+   
 .. versionchanged:: 3.2
    Implement the Sequence ABC.
    Support slicing and negative indices.