Context: Requirements scoping is one of the key activities in requirements management but also a major risk for project management. Continuously changing scope may create a congestion state in handling the requirements inflow which causes negative consequences, e.g. delays or scope creep. Objectives: In this paper, we look at requirements scoping literature outside Software Product Line (SPL) by exploring the current literature on the phenomenon, summarizing publication trends, performing thematic analysis and analyzing the strength of the evidence in the light of rigor and relevance assessment. Method: We run a Systematic Mapping Study (SMS) using snowballing procedure, supported by a database search for the start set identification, and identified 21 primary studies and 2 secondary studies. Results: The research interest in this area steadily increases and includes mainly case studies, validation or evaluation studies. The results were categorized into four themes: definitions, negative effects associated with scoping, challenges and identified methods/tools. The identified scope management techniques are also matched against the identified requirements scoping challenges.