Groups collaborating in online spaces on complex, extended projects develop behavioral conventions and agreed-upon practices to structure and regulate their interactions and work. Collaborators on Wikipedia have developed a multi-tiered policy environment to document a set of evolving principles, processes, and rules to facilitate productive group collaboration. Previous quantitative studies have noted this hierarchical structure, but have evaluated the policy environment as a singular entity rather than investigating potential differences between the three main regulatory genres that enable it. These studies also excluded essays, the least official regulatory genre, from their analyses. We perform a comparative content analysis of all three genres (policies, guidelines, and essays) and demonstrate that they focus on different areas of community regulation. Drawing on the theory of genre ecologies we discuss the possible role of unofficial genres such as essays in articulating and regulating work practices in online, organized collaborative work.