Hi Wayne;
I remembered reading about something like this a while ago.
Check the website:
http://ldaps.arc.nasa.gov/LEGOEngineer/
Check the "Teacher's Guide". One of the downloads is a guide for the
icons.
Also check the official Robolab webpage:
http://www.lego.com/dacta/robolab/default.htm
Regards;
Enrique
www.vartortech.com