Julia Black's book is the first authoritative study of rulemaking in one of the most important areas of economic life: financial services. The books has three main aims: first, to build a jurisprudential and linguistic analysis of rules and interpretation, drawing out the implication of these analyses and developing quality proposals for how rules could be used as instruments of regulation. Second, it interprets that analysis and set of proposals with an empirical study of the formation and use of rules in a particular regulatory system: financial services, and third, it evaluates the nature of the rulemaking process. The author's main case study, examining the use of self-regulation in the financial services sector, complements the detailed analysis of rule formation and uses. The book will be an invaluable addition to the libararies of all administrative lawyers and anyone with an interest in the provision and regulation of financial services.