Add rules for indenting continuation lines.

pep-0008.txt

@@ -57,6 +57,29 @@ Code lay-out
     For really old code that you don't want to mess up, you can continue to
     use 8-space tabs.
 
+    Continuation lines should align wrapped elements either vertically using 
+    Python's implicit line joining inside parentheses, brackets and braces,
+    or using a hanging indent of double your code indention, in which case 
+    there should be no argument on the first line. For example:
+
+    Yes:  # Aligned with opening delimiter
+          foo = long_function_name(var_one, var_two,
+                                   var_three, var_four)
+
+          # Double code indention for hanging indent; nothing on first line
+          foo = long_function_name(
+                  var_one, var_two, var_three,
+                  var_four)
+
+    No:   # Stuff on first line forbidden
+          foo = long_function_name(var_one, var_two,
+              var_three, var_four)
+
+          # 2-space hanging indent forbidden
+          foo = long_function_name(
+            var_one, var_two, var_three,
+            var_four) 
+
   Tabs or Spaces?
 
     Never mix tabs and spaces.