This preliminary notice has to explain to the contract-holder the nature and effect of the change and invite them to comment on the proposed change within a certain time.
Mae'n rhaid i'r hysbysiad rhagarweiniol hwn esbonio natur ac effaith y newid i ddeiliad y contract a'i wahodd i wneud sylwadau ar y newid arfaethedig o fewn cyfnod penodol.