The restricted verticality perspective in researching informal networks : concepts, definitions and theoretical approaches to informality -- Empirical research on informal social phenomena and the limitations of formal methods -- Exiting the emic-etic logic : how to conduct successful fieldwork on informal phenomena -- Thinking beyond sectors : informal economy and informal networks -- Escaping locality : ethnography beyond systems, zones, countries and sites -- Interfaces between the formal and the informal : actors, places and routes.