diff --git a/zsnes/src/md.psr b/zsnes/src/md.psr
index 663b22c4..acb898bd 100644
--- a/zsnes/src/md.psr
+++ b/zsnes/src/md.psr
@@ -4,6 +4,10 @@ md_prog times 50 db "mencoder"
 md_raw times 100 db "-demuxer rawvideo -rawvideo format=0x42475218:w=256:h=224:size=172032"
 md_other times 50 db "-aspect 4/3 -mc 0 -nosound"
 md_file times 50 db "video.avi"
+@Valid variables to use in the next three lines are:
+@$md_prog, $md_raw, $md_other, $md_file, $md_video_rate
+@These variables are defined above.
+@$md_video_rate is $md_ntsc or $md_pal depending on the game as needed
 md_uncompressed times 150 db "$md_prog $md_other $md_raw:fps=$md_video_rate -ovc copy -o $md_file -"
 md_x264 times 150 db "$md_prog $md_other $md_raw:fps=$md_video_rate -ovc x264 -x264encopts qp_constant=0:frameref=15 -o $md_file -"
 md_ffv1 times 150 db "$md_prog $md_other $md_raw:fps=$md_video_rate -ovc lavc -lavcopts vcodec=ffv1:vstrict=-2 -o $md_file -"