Hi lk280king, In fact you have to export left hand on channel 3 and right hand on channel 4 of your midi file. In my case, I use MuseScore. I create a sheet with 4 instruments. I put left hand on the 3rd instrument and I put right hand on the 4th instrument. 1st and 2nd are empty That's work fine. To answer to my question, I've just an answer from casio. It's not possible to add marks Bad luck