+(defcustom spam-stat-score-buffer-user-functions nil
+ "List of additional scoring functions.
+Called one by one on the buffer.
+
+If all of these functions return non-nil answers, these numerical
+answers are added to the computed spam stat score on the buffer. If
+you defun such functions, make sure they don't return the buffer in a
+narrowed state or such: use, for example, `save-excursion'. Each of
+your functions is also passed the initial spam-stat score which might
+aid in your scoring.
+
+Also be careful when defining such functions. If they take a long
+time, they will slow down your mail splitting. Thus, if the buffer is
+large, don't forget to use smaller regions, by wrapping your work in,
+say, `with-spam-stat-max-buffer-size'."
+ :type '(repeat sexp)
+ :group 'spam-stat)
+