I know this was brought up several years ago and it sounded like it was in the works then, (I sure can't find a way to do it though), but a way to filter certain file types to exclude them from the library would really be a great feature. I've run into the problem with raw photos that was brought up
in this thread on a newer Sony player, so every time it comes to a raw image, it takes the time in the slideshow to display the broken image icon. For editing purposes, keeping the raw image with the other jpgs is a must, plus it's great to see the before and after edited photos. Oddly this is a new stumbling block for me with the newest player because my 2 older Sony players in the same line do display raw images perfectly (even though they're also not listed as supporting .arw images).