As far as I know the newest tag definition IDv2.3 offers a new tag field "FMPS_Rating" which could contain the user rating for the song. Its a value of 0.0,....,1.0 where the floating point values are mapped as follows to the "usual" 0 to 5 stars:
0.0 or empty = No star/No rating
0,01...0,2 = 1 Star
....
0,81....1.0 = 5 Stars
Unfortuantely Mp3tag does not offer a corresponding column which shows the current value in this tag.
Can this column be added?
Thank you
Peter