“Tenements used as dwelling-houses” are exempted from the mode laid down for assessing the tenements occupied by the Railway Corporation (and some other bodies) in the Assessment and Rating (Public Utility Corporations) Ordinance (Cap. 16, the 1958 Laws, vol. I, p. 129, Section 3). All overseas officers live in houses in the Railway compounds, each in what is a self-contained dwelling-house; it is part of their conditions of service that they should be provided with living quarters; but they have to pay rent, which is reckoned at so much per annum as a percentage on salary but not exceeding 150. The houses are allocated by the Corporation, but while in occupation an employee has all the privileges of any ordinary tenant. He must, however, vacate his house when he ceases to be in the Corporation’s employ, or goes on transfer or on leave.”