http://www.flickr.com/photos/arenamontanus/264112997/in/set-72157594323393196/I saw this appropriate symbol in a set of imaginative warning signs.
A few of those signs made me laugh… Maybe our team will take that autonomous warning sign, make a sticker, and plaster it to our bot. 
Very cool! And then there’s a bit more simpler options such as http://www.warninglabelgenerator.com/
I think I have a warning label saved somewhere on my computer that says “Warning: All photos taken with this camera may be photoshopped” but I keep forgetting to put it on my camera.
Heidi
That symbol should be required on my team’s robot, and probably on a few others as well.