are internal structures, unexposed to the end-user as you suggest. For me, a seekpoint describes an offset in the audio file, and enables any player to jump to instantly jump to that position. For instance, if you pack up an a collection of audio tracks into a single FLAC file, there is a strong need for seeking ! It is common, typically in classical music, to have up to 40 tracks on a single CD (exemple: sets of variations, etudes ...) and it is much more handy to join them into a single FLAC, instead of having tens of mini FLAC files. But then you need seekpoints. So the questions still holds: 1. how can i check if the seekpoints i specified when encoding are actually there ? 2. what media players are aware of FLAC seekpoints ? Phil