The app on start up sends a chat message to the server with the check sum of the rules file and the app itself so you can check for tampering. Also a rules.ini file where a league admin can select what rules to use. The app has a user preferences.ini file where they can set the size and various options like a beep for valid DRS. Outside of DRS zones the background colour disappears and only the DRS text and penalties (if any) are displayed. Here on lap 4 you can see the valid DRS icon, if I had used DRS further at incorrect times a number would be shown next the penalty flag.
