I have heard people say that rejections are thin letters and thick ones are acceptances. When I was accepted to Cincy it was a thin letter (2 pages to be exact). The first page was the congrats and the second page was a form to sign and return to confirm acceptance. They send out everything else throughout the year. I knew I was accepted because of the website and my boss confirmed that he had known for a few days but then I got a thin letter and I must say I was a little worried. I could just see, "Sorry, we made an error"