I suppose I don't have to now I have a delete book option with the Lbook firmware before after I finished a book I would just leave it on there after while the folder was just full of files so I would delete them. I like my SD Card neat and Tidy.
I delete the Digital Editions folder too when I accidentally open up a EPUB in ADE instead of CR. I wish it was the other way around, short press CR and long press ADE. I can never get the press long enough sometimes. lol