search through the 'skin.ini' file in the 'skins\base' folder of your bsplayer directory. The text after the semicolons gives you most of the information you will need. There was also a previous post which gave all/most of the available actions for buttons. I'm not sure what exactly the 'rgn.dat' file is for, but i know that it is not required. If you have any other specific questions, i'll answer them.