Fixed the note about charset encoding in PO files. It must be UTF-8 since [5708].

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6461 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/i18n.txt

@@ -456,10 +456,13 @@ otherwise, they'll be tacked together without whitespace!
 
 .. admonition:: Mind your charset
 
-    When creating a ``.po`` file with your favorite text editor, first edit
+    When creating a PO file with your favorite text editor, first edit
     the charset line (search for ``"CHARSET"``) and set it to the charset
-    you'll be using to edit the content. Generally, utf-8 should work for most
-    languages, but ``gettext`` should handle any charset you throw at it.
+    you'll be using to edit the content. Due to the way the ``gettext`` tools
+    work internally and because we want to allow non-ASCII source strings in
+    Django's core and your applications, you **must** use UTF-8 as the encoding
+    for your PO file (this means that everybody will be using the same
+    encoding, which is important when Django processes the PO files).
 
 To reexamine all source code and templates for new translation strings and
 update all message files for **all** languages, run this::