So you think you know enough about file suffixes, or extensions as they are often called? DOC, TXT, TIF, GIF, DXF and JPEG may be all you really need.
Until, that is, at 17. 30 on a Friday you find you have downloaded a file which you know you have to use and there's no one around to tell you in what program it will open. What, for example, if it were an RD1 file? Several websites offer explanations.
And RD1 files? You'd have to be an aficionado of the classic computer game Descent to need to know that.
whatis.techtarget.com/Flat_Files/WhatIs_File_ Format_X/0,282018,,00.html www.kresch.com/exts/ext.htm