designing a new system of bands and tax rates that is more progressive, including considering adding more bands to the top and bottom ends of the scale if needed
cynllunio system newydd o fandiau a chyfraddau treth sy'n fwy blaengar, gan gynnwys ystyried ychwanegu rhagor o fandiau ar ben uchaf a phen isaf y raddfa os oes angen