Occlusion is most commonly presented as an aspect of certain genres: occluded genres. Here, occlusion is proposed as a property of the processes by which genres are taken up. While routine use of genres creates expectations around when the genre’s uptake is commonly occluded, such expected practice can be subverted by deliberate disclosure. Occlusion and disclosure in the process of genre uptake thus become argumentative and powerful moves in communicative interaction. In three case studies, I analyze processes of occlusion in relationship to the genre of the letter to the university president.