The Council Tax and Non-Domestic Rating (Demand Notices) (England) Regulations 2003

5.  A statement of the days (if any) on which, for the purposes of calculating the payments required to be made under the notice it was understood or assumed that—

(a) the chargeable amount would fall to be calculated under section 43(5) or 45(5) of the 1988 Act;

(b) the chargeable amount would fall to be calculated by reference to section 44(2) and (2A) of the 1988 Act as substituted by section 44A(7) or (9) of that Act; or

(c) rules under section 47(1)(a) or 58(3)(a) of the 1988 Act would apply;

together with a statement of the manner in which the chargeable amount for those days was calculated and of the amount by which the aggregate amount demanded under the notice is reduced as compared with the amount which would have been demanded if section 43(4), without modification, and (so far as is relevant) section 44(2) without substitution, or (as the case may be) section 45(4), applied to the calculation of the chargeable amount for those days.