The WWF format is a PDF that cannot be printed out. It's a simple way to avoid unnecessary printing. So here's your chance to save trees and help the environment. Decide for yourself which documents don't need printing out -- then simply save them as WWF.
Download software: http://www.saveaswwf.com
See also previous post: Forget the PDF, save a tree, save as WWF in December.
Jung von Matt, Hamburg, Germany