There is no big difference between file constructions for Ringtone which include Mfi and SMAF, and SMF. They have file headers on the top, followed by their truck data. MIDI(SMF) file header which is on top of a file includes fields such as copyrights and song titles, however, it is not programmed to prohibit saving nor transferring downloaded files. As you know, it doesn�ft make sense to do so because we can make file copies �gbasically free�h using Explorer. Mfi and SMAF file headers include similar fields to MIDI(SMF) ones. Furthermore, they include additional fields which ask file save permission and record how many times the file has been transferred. Since Ringtone files cannot be copied using Explorer like PC ones, it�fs necessary to use mobilephones to transfer them as attached files. That is why Mfi and SMAF are programmed to refuse those illegal copies and restrict mobilephones to apply Ringtones.