@@ -135,11 +135,13 @@
   Enter a SQL statement to edit the current picture. This should be a
   UPDATE statement which updates the column called "C" of the table called
   "GRAPH". It has columns "X" and "Y" which are the coordinates of the
   pixel, and "C" which is the colour of the pixel. It may also be a SELECT
   statement in order to query it, and the response is then displayed
-  (which must be a single row and single column only).
+  (which must be a single row and single column only). This table also has
+  a column "S" which is the same for all rows, and is the size of the
+  picture, which can be used in macros (see config.doc).
 
 ` or =
   Exchange the current picture with the spare page. (The spare page is not
   stored in the puzzle set; it is lost when Free Hero Mesh is terminated.)