While there are many examples of incidents that make the need for more work around the human aspects of security apparent, the literature makes it obvious that usable security can mean many different things and usable security is a complex matter. This paper reports on a structured literature review that analyzed what the research community considers to be included in the term "usable security". Publications from the past five years were analyzed and different perceptions of usable security were gathered. The result is a listing of the different aspects that are discussed under the term "usable security" and can be used as a reference for future research of practitioners who are developing security functions with usability in mind.