remove :c:data: which snuck in
diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst
index 83fa520..68dc9d6 100644
--- a/Doc/extending/extending.rst
+++ b/Doc/extending/extending.rst
@@ -266,7 +266,7 @@
sts = system(command);
-Our :func:`spam.system` function must return the value of :c:data:`sts` as a
+Our :func:`spam.system` function must return the value of :cdata:`sts` as a
Python object. This is done using the function :cfunc:`PyLong_FromLong`. ::
return PyLong_FromLong(sts);