The outcome of the principal proceedings would be the outcome relating to any order for costs of the proceedings: see Brotherton v Metropolitan District Railway Joint Committee [1894] 1 QB 666. Although the words "follow the event" may mean "according to who wins", (see Davies v Eli Lilly & Co [1987] 1 WLR 1136; [1987] 3 All ER 94, per Donaldson MR (at 1143; 99), per Lloyd LJ (at 1144; 100-101), per Balcombe LJ (at 1146; 102) unless an order is made in respect of costs there would be no event in respect of which the provisions of r15 could operate. If no order for the payment of costs is made on disposal of the cause or matter, or an order is made that no costs be paid, no foundation for the taxation of the reserved costs would be provided by r 15. The effect of the rule, therefore, is to make reserved costs of interlocutory proceedings costs in the cause of the successful party in the principal proceedings unless some other order is made in respect of them.