The Eaton Collection of Science Fiction & Fantasy at the University of California, Riverside contains a unique archive of slash fan fiction and yaoi/boys' love (BL) manga. Slash and BL refer to fanmade or commercially published works of male homosexual erotica or romance historically made for the pleasure and consumption of women. These fandoms have been a minor subject of academic scholarship for years, though few archives or libraries are actively acquiring them. In this article, we explore the value and challenges associated with collecting materials containing taboo subject matter. We contextualize this process with an overview of the history of archival theory, the emergence of critical archive studies, and the intersection of niche fan communities with feminist and queer studies frameworks.