Urban studies as a field of inquiry aims to explore the urbanization trends, socioeconomic conditions, sustainability indicators and resilience of people, places, and systems for the twenty-first century.^[1] The fragmented nature of urban concepts requires a domain knowledge organization system that integrates knowledge from various disciplines to facilitate effective urban information retrieval and semantic interoperability. Urban knowledge organization is to classify knowledge systems and analyze the definitions of concepts and their semantic relationships accommodating multiple views and their epistemological foundations of urban discourses. This system aims to integrate diverse aspects of urbanism to facilitate an organized urban information system for information retrieval. To understand urban information needs, it is important to know the diversity of urban resources, as there is little discussed on mapping urban as a subject in strengthening urban knowledge base, especially how it is captured in library classification schemes, subject headings list, thesauri, ontologies and registries.

This chapter aims to assess the urban concepts developed by prominent urban vocabularies that map the key concepts and themes. Also, the challenges associated with determining the “aboutness” of urban subjects and the relationships urban concepts share in the controlled vocabularies are explored. Through a cross-disciplinary analysis, it has been found that urban vocabularies with urban ontologies and registries are enhancing integrated semantic discoverability and linked data services for urban information retrieval.