File Extension RTF it is safer to open an attachment if it is save in Rich Text Format (RTF). Some advantages of this type of file format is that it has a virus-free method of saving and transferring documents. So you may ask how about other document formats, like .DOC or .DOCX? In DOC or DOCX format hidden macros attachment are allowed, with this capability a virus can be easily hidden in a DOCX file as macro, and there’s a probability that a computer will be infected once this file with hidden macro virus will be opened. As an addition advantage of File Extension RTF is that this file is pretty small so you don’t have any problem in transferring the file.

Every time I make a program in Java I save my source code in File Extension RTF because of the fast parsing speed impression. You can also easily convert RTF into HTML + CSS or to XHTML. The .rtf format is one of those that are commonly supported by majority word processing software.