I have a Kindle, and I am increasingly using it to display documents such as Board Agendas, Minutes, reports I am due to present, etc. In order to load them from my PC/laptop, I have to save the (usually Word/Excel) originals as PDFs. Once I transfer them, I notice that I end up with two documents on the Kindle; xyz.pdf and xyz.pdr. Are they interdependent, or can I get rid of the pdf file once the pdr one is up and running?