A fix for issue 1974, inspired by the patch from Andi Albrecht (aalbrecht),
though with some changes by me. This patch should not be back ported or
forward ported. It's a bit too risky for 2.6 and 3.x does things fairly
differently.
diff --git a/Doc/library/email.header.rst b/Doc/library/email.header.rst
index 000d48e..e424dff 100644
--- a/Doc/library/email.header.rst
+++ b/Doc/library/email.header.rst
@@ -74,7 +74,8 @@
Optional *continuation_ws* must be :rfc:`2822`\ -compliant folding whitespace,
and is usually either a space or a hard tab character. This character will be
- prepended to continuation lines.
+ prepended to continuation lines. *continuation_ws* defaults to a single
+ space character (" ").
Optional *errors* is passed straight through to the :meth:`append` method.