--- doc/homework/analyze_structure	2007/08/20 21:58:22	1.1
+++ doc/homework/analyze_structure	2007/08/22 10:16:50	1.2
@@ -16,6 +16,12 @@ For the rest of the keys $prefix will be
                                or statically set (and thus likely the same
                                for each student)
 
+   - $prefix.bubble_lines    - Number of lines of bubbles in a scantron
+                               sheet required for this response.  This is used
+                               to know exactly what it means to multiply bubble
+                               or to not have bubbles for a response in exam
+                               mode taken on scantron sheets.
+
 <numerical/formularesponse>
 
     - $prefix.type - either 'numericalresponse or 'formularesponse'