Feminist, queer, and trans studies are all influenced significantly by anti-identitarian thought. Yet, contemporary gender and sexual identities only seem to be proliferating: nonbinary, graysexual, demigender, and more. This chapter focuses on a series of reference guides that schematize this recent expansion. Often miming reductive reference forms (the dictionary, the A-Z list), these texts and the questions they raise help to rethink the place of ‘identity’ across gender and sexuality studies.