complete cgi.parse() signature; thanks to Aaron Bingham from docs@
diff --git a/Doc/library/cgi.rst b/Doc/library/cgi.rst
index b95f131..0240998 100644
--- a/Doc/library/cgi.rst
+++ b/Doc/library/cgi.rst
@@ -284,10 +284,10 @@
 algorithms implemented in this module in other circumstances.
 
 
-.. function:: parse(fp[, keep_blank_values[, strict_parsing]])
+.. function:: parse(fp[, environ[, keep_blank_values[, strict_parsing]]])
 
    Parse a query in the environment or from a file (the file defaults to
-   ``sys.stdin``).  The *keep_blank_values* and *strict_parsing* parameters are
+   ``sys.stdin`` and environment defaults to ``os.environ``).  The *keep_blank_values* and *strict_parsing* parameters are
    passed to :func:`urlparse.parse_qs` unchanged.