Participatory fans on Tumblr adopt specialized fandom tags, which are unlikely to be used by Tumblr members who do not identify with a particular fandom or subsection of fandom. Such tags are not merely composed of the name the fandom (such as a show or movie title), or even one of the primary characters. Rather, specialized fandom tags further delineate the potential audience, trying to draw the attention of a specific subsection of the larger fan base or to conceal content from other fans (and content producers) who do not want to view romantic or sexual content. In using these tags, widely scattered fans take on some characteristics of communities. Norms develop regarding what is posted and how fans interact with each other when a particular tag is deployed. Without an architecturally defined community structure, content and conduct are nonetheless debated and controlled.