Clarify encoding cookie format.

pep-0263.txt

@@ -47,17 +47,26 @@ Defining the Encoding
 
     To define a source code encoding, a magic comment must
     be placed into the source files either as first or second
-    line in the file:    
+    line in the file, such as:
+
+          # coding=<encoding name>
+
+    or (using formats recognized by popular editors)
 
           #!/usr/bin/python
           # -*- coding: <encoding name> -*-
 
+    or
+
+          #!/usr/bin/python
+          # vim: set fileencoding=<encoding name> :
+
     More precisely, the first or second line must match the regular
     expression "coding[:=]\s*([-\w.]+)". The first group of this
     expression is then interpreted as encoding name. If the encoding
     is unknown to Python, an error is raised during compilation. There
     must not be any Python statement on the line that contains the
-    encoding declartation.
+    encoding declaration.
 
     To aid with platforms such as Windows, which add Unicode BOM marks
     to the beginning of Unicode files, the UTF-8 signature