Alert Light Help

I had an alert light come on and go off as I was driving to work today that I can't figure out. I drive a 2005 Prius, the alert light was the ! in a triangle on the dash but the odd symbol was on the info screen in a brown box. It was an oval with the left side flattened with four downward slanting lines coming from the flattened side and an arrow pointing back over the oval at the top and bottom of the lines. Looks a bit like a headlight with down pointing beams facing left to me. The car was driving fine and it the alert went out for awhile then came back as I drove. Anyway I can't find where the alert symbols are in the owners manual, can someone point me where I should be looking for this symbol in the manual or tell me what it means? Any help here would be appreciated.

 

Thanks for that, I am taking it in early next week anyway, I will have them look at it then. Thanks also for the page numbers, I am grabbing it now and check it.