(1) A self assessment made by a chargeable person under section 959R shall be made by reference to the particulars contained in the chargeable person's return for the chargeable period involved.
(2) A self assessment amended by a chargeable person under section 959V shall be amended by reference to the particulars contained in the chargeable person's return, as amended by notice under that section, for the chargeable period involved.
(3) A self assessment made by a Revenue officer in relation to a chargeable person under section 959U shall be made by reference to the particulars contained in the chargeable person's return for the chargeable period involved.
(4) Nothing in this Chapter prevents a Revenue officer from making a Revenue assessment on a chargeable person under Chapter 5 and where a Revenue officer makes an assessment under that Chapter any self assessment previously made under this Chapter shall, for the purposes of determining the chargeable person's liability to tax
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