(1) For the purposes of the meaning assigned to 'chargeable person' in section 959A, it does not include a person -

(a) whose only source or sources of income for a tax year is or are sources the income from which consists of emoluments to which Chapter 4 of Part 42 applies, but for this purpose a person who, in addition to such source or sources of income, has another source or other sources of income shall be deemed for the tax year to be a person whose only source or sources of income for the tax year is or are sources the income from which consists of emoluments to which Chapter 4 of Part 42 applies if the income from that other source or those other sources, which does not exceed €5,000 in total -

(i) is taken into account in determining the amount of his or her tax credits and standard rate cut-off point for the tax year applicable to those emoluments, or

(ii) is fully taxed at source under section 261,

and, for the purposes of deciding whether such income should be taken into account in determining the amount of tax credits and standard rate cut-off point for the tax year, the Revenue Commissioners may have regard to the amount for that, or any previous, tax year of the income of the person from that other source or those other sources before deductions, losses, allowances and other reliefs,