These "franchise fees" were mostly calculated according to the value of the retailer's sales in a specific "preceding" period, rather than on the value of goods currently being sold. Although these seem similar to excise duties, a series of High Court precedents had effectively "quarantined" such fees from disallowance in the areas of liquor retailing, tobacco retailing, and petrol distribution. In 1997, by a bare majority, the High Court decided that this area of doctrinal quarantine was incoherent with the rest of the law relating to excise duties and removed it.