s 5 Application to offices and office-holders
(1) The provisions of the employment income Parts that are expressed to apply to employments apply equally to offices, unless otherwise indicated. (2) In those provisions as they apply to an office— (a) references to being employed are to being the holder of the office; (b) “ employee ” means the office-holder; (c) “ employer ” means the person under whom the office-holder holds office. (3) In the employment income Parts “ office ” includes in particular any position which has an existence independent of the person who holds it and may be filled by successive holders.