The act of mapping entails drawing, naming and populating categories. These categories exist in urban planning both as a planning tool and as a political and economic tool. This chapter explores how this double dimension, and the tension between the two aspects, are revealed by the controversies and struggles around the DP. Recasting the origins and the nature of categories in the DP, it analyses their use in relation to the different versions of the DP through a series of case studies. It asks how DP categories were produced, used, owned and contested by diverse social and economic interests in order to gain control over certain aspects of the city. As categories contribute to producing and maintaining an urban “order”, the politics of categories are analysed in relation to the trajectories of urban growth. Recognizing the fluidity of urban space in everyday practices, the chapter concludes with a reflection on the role of boundaries in contemporary forms of politics.