Index: Doc/library/textwrap.rst
===================================================================
--- Doc/library/textwrap.rst	(revision 86565)
+++ Doc/library/textwrap.rst	(working copy)
@@ -121,7 +121,14 @@
          each tab character will be replaced by a single space, which is *not*
          the same as tab expansion.
 
+      .. note::
 
+         If :attr:`replace_whitespace` is false, newlines may appear in the
+         middle of a line and cause strange output. For this reason, text should
+         be split into paragraphs (using :meth:`str.splitlines` or similar)
+         which are wrapped separately.
+
+
    .. attribute:: drop_whitespace
 
       (default: ``True``) If true, whitespace that, after wrapping, happens to