[Terisa de morgan]

Rereading chaley's message I've been aware that I'm too "up-to-date". I still have a column which makes something similar (composite and stars....), that I've been using for showing half stars.

You can define the function for "my_ratings" and, instead of using the standard rating columns with stars that calibre shows", you can define icons for the column associated to its value, so you can get the same effect.

Yes, it will be recomputed... as any custom column... but it can be done.