214. The revenue should be arranged under compre. hensive heads. It falls generally into four broad classes «— (1) Duties. taxes, licences, &c.; (2) Receipts for, or in aid of, specific Govern- ment services—such as fees or hospital receipts; (3) Receipts on account of undertakings of a commercial character; and (4) Revenue from Government property, such as land, houses, and investments. It will be convenient to have several heads for each of these classes, but care should be taken that no head comprises items coming under different classes, and that revenue derived from taxation is easily distin- guishable from revenue not so derived. 215. Stamp Duties should not form a separate head. If the same description of stamp is sold for different revenue purposes, and there is thus no means of dis- tinguishing the use to which the stamp is put, the total receipts from such stamps should be provided for under a separate subhead ‘‘ Stamps sold for various revenue purposes ’’ under the head for licences, or that for payments for specific services, according to the nature of the bulk of the receipts. 216. The proceeds of the sale of Government lands and premiums on leases should be kept distinct in the Estimates from the total revenue from other sources. 217. In Colonies where a temporary deficit is to be met by a loan from Imperial funds, the estimate of the amount to be so received should appear under a separate head following and distinct from the total receipts from other sources; and any anticipated re- payments of such loans should appear under a sepa- rate head of expenditure, following and distinct from the total of other expenditure. If the Colony is receiving a grant from Imperial funds to meet certain