From Bill Betts' website - with permission.
http://www.culture-crop.com/cropcirclepreuvemanmade.htm The captions read : "Before 26 June 2004", and "After 26 June 2004". The message is: 'This is how circlemakers could prove that they made a formation". [- and still remain anonymous]. One of the many ways in which they could prove the origins of a formation before the event. The problem is that any photo can be manipulated. Perhaps a better way would be to post (snail post) a diagram of the intended formation to some impartial observer before making a formation. The problem then is to find an impartial observer whose word would be generally accepted. There must be some way to set this up!