In the Urban Informatics session of the Computational Urban Planning and Urban Management (CUPUM 2019) conference (where we started the idea of this special issue), there were heated discussions on the fundamental meaning of the term "urban informatics". Questions revolved around its definition, its role in urban planning, and more specifically, its role in planning support technology. Some consider urban informatics a vehicle for the "seamless transitioning between the visible and the invisible infrastructure of cities" (Foth, 2011). Some see it as an extension of "big data" (Schintler, 2017), while others a field that simply "applies information technologies in urban areas" (Thakuriah et al., 2017). Although it is not our intent to provide defining terms and definitions, some lexicography will help with the discussion. An early definition of "informatics" is provided by Mikhailov et al. (1967) as: ".. . the processes, methods and laws related to the recording, analytical-synthetical processing, storage, retrieval and dissemination of scientific information" (transcribed by Wellisch, 1972, p. 176). This is a wide-ranging and extensive definition that touches on almost every aspect of applied information science. Its extensiveness has created some difficulty in delineating the scope of sub-disciplinary areas of study that have emerged around the concept. The urban informatics literature is generally focused on urban computing and computer science techniques to explore, describe, predict, and to a lesser extent, explain