PDF documents are a very popular document format for everything from Assignment submissions, papers, to minutes from meetings. Just like word documents comments can be added to PDF documents for example feedback on your essay submission.
A common problem faced is when the document is printed out. For example, students like to be able to see both their submission text and the comments made on the same page this guide shows what preferences you need to have in Adobe Reader and print settings selected at the point you send the document to print to be able to achieve this.
Reading On Screen 