more updates on the extension API

--HG--
branch : trunk
diff --git a/jinja2/nodes.py b/jinja2/nodes.py
index 0d921a7..2519682 100644
--- a/jinja2/nodes.py
+++ b/jinja2/nodes.py
@@ -742,7 +742,8 @@
 
 class InternalName(Expr):
     """An internal name in the compiler.  You cannot create these nodes
-    yourself but the parser provides a `free_identifier` method that creates
+    yourself but the parser provides a
+    :meth:`~jinja2.parser.Parser.free_identifier` method that creates
     a new identifier for you.  This identifier is not available from the
     template and is not threated specially by the compiler.
     """