I believe, the prefix and suffix are Numbers you can assign to your renders. For Example, I have a scene that I want to animate from two different viewpoints and splice together in Premiere. I also want them to be rendered as Tiff Files to preserve file quality and transparency. (Okay, a little hokey) So I change the prefix to 1 and the suffix to one to have Carrara render my images with the file name 1blah01.tif - 1blah25.tif. Then for the second round I change the prefix to 2 to differentiate between the cameras. so I get 2blah1.tif - 2blah25.tif. Just a nice touch. Course I would jsut put them in seperate directories... :) Hoborg