We use the yellow paper in our fax machine so we can easily and quickly tell the difference between faxes and copies. Also it makes it easy to find a fax in a file or see it when someone puts it on your desk.
Good stuff. I am just sorry that it is made from wood pulp which brings down trees and uses hydrochloric and sulfuric acids to process. A much cleaner and safer alternative is hemp paper. Staples should offer this as an alternative. I would buy that instead.