Additional clarifications based on discussion amongst the PEP authors.

pep-0008.txt

@@ -78,14 +78,14 @@ Use 4 spaces per indentation level.
 
 Continuation lines should align wrapped elements either vertically
 using Python's implicit line joining inside parentheses, brackets and
-braces, or using a hanging indent.  When using a hanging indent the
+braces, or using a *hanging indent* [#fn-hi]_.  When using a hanging
-following considerations should be applied; there should be no
+indent the following considerations should be applied; there should be
-arguments on the first line and further indentation should be used to
+no arguments on the first line and further indentation should be used
-clearly distinguish itself as a continuation line.
+to clearly distinguish itself as a continuation line.
 
 Yes::
 
-    # Aligned with opening delimiter
+    # Aligned with opening delimiter.
     foo = long_function_name(var_one, var_two,
                              var_three, var_four)
 
@@ -95,25 +95,54 @@ Yes::
             var_four):
         print(var_one)
 
+    # Hanging indents should add a level.
+    foo = long_function_name(
+        var_one, var_two,
+        var_three, var_four)
+
 No::
 
-    # Arguments on first line forbidden when not using vertical alignment
+    # Arguments on first line forbidden when not using vertical alignment.
     foo = long_function_name(var_one, var_two,
         var_three, var_four)
 
-    # Further indentation required as indentation is not distinguishable
+    # Further indentation required as indentation is not distinguishable.
     def long_function_name(
         var_one, var_two, var_three,
         var_four):
         print(var_one)
 
+The 4-space rule is optional for indentation lines.
+
 Optional::
 
-    # Extra indentation is not necessary.
+    # Hanging indents *may* be indented to other than 4 spaces.
     foo = long_function_name(
       var_one, var_two,
       var_three, var_four)
 
+This PEP explicitly takes no position on how or whether to further
+visually distinguish continuation lines after multi-line ``if``
+statements.  Some acceptable options include::
+
+    # No extra indentation.
+    if (this
+        and that):
+        do_something()
+
+    # Add a comment, which will provide some distinction in editors
+    # supporting syntax highlighting.
+    if (this
+        and that):
+        # Since both conditions are true, we can frobnicate.
+        do_something()
+
+
+    # Add some extra indentation on the conditional continuation line.
+    if (this
+            and that):
+        do_something()
+
 The closing brace/bracket/parenthesis on multi-line constructs may
 either line up under the first non-whitespace character of the last
 line of list, as in::
@@ -183,7 +212,7 @@ exclusively or primarily by a team that can reach agreement on this
 issue, it is okay to increase the nominal line length from 80 to
 100 characters (effectively increasing the maximum length to 99
 characters), provided that comments and docstrings are still wrapped
-at 72 characters.  
+at 72 characters.
 
 The Python standard library is conservative and requires limiting
 lines to 79 characters (and docstrings/comments to 72).
@@ -1155,6 +1184,16 @@ Programming Recommendations
     automated utilities could be supported.
 
 
+.. rubric:: Footnotes
+
+.. [#fn-hi] *Hanging indentation* is a type-setting style where all
+   the lines in a paragraph are indented except the first line.  In
+   the context of Python, the term is used to describe a style where
+   the opening parenthesis of a parenthesized statement is the last
+   non-whitespace character of the line, with subsequent lines being
+   indented until the closing parenthesis.
+
+
 References
 ==========
 
@@ -1168,6 +1207,7 @@ References
 .. [4] PEP 8 modernisation, July 2013
    http://bugs.python.org/issue18472
 
+
 Copyright
 =========