This document is the result of a year of work and collaboration by the Trans Metadata Collective (TMDC; https://transmetadatacollective.org/), a group of dozens of cataloguers, librarians, archivists, scholars, and information professionals with a concerted interest in improving the description and classification of trans and gender diverse people in GLAMS (Galleries, Libraries, Archives, Museums and Special Collections). The Collective’s primary goal was to develop a set of best practices for t...