Last round of adapting style of documenting argument default values.
diff --git a/Doc/library/urllib.error.rst b/Doc/library/urllib.error.rst
index 714ee47..282329f 100644
--- a/Doc/library/urllib.error.rst
+++ b/Doc/library/urllib.error.rst
@@ -39,7 +39,7 @@
to a value found in the dictionary of codes as found in
:attr:`http.server.BaseHTTPRequestHandler.responses`.
-.. exception:: ContentTooShortError(msg[, content])
+.. exception:: ContentTooShortError(msg, content)
This exception is raised when the :func:`urlretrieve` function detects that
the amount of the downloaded data is less than the expected amount (given by