Today, researchers and practitioners in the fields of English for Academic Purposes (EAP), English for Specific Purposes (ESP), and first and second language writing research overwhelmingly acknowledge that knowledge about just discoursal forms and disciplinary genres is not enough for students to become proficient in their disciplines (Beaufort 1999; Ivanič 1998; Prior 1998; Swales 2004; Tardy 2009). Even so, many studies continue to focus on surface-level analyses, limited either to the text that is explicitly identifiable on the page, or to describing the context alongside the text. As discussed by Lillis (2008), and Starfield (2011), many such studies examine context as though it were "talk around text" (Lillis 2008). By positioning their research from the outside looking in, researchers are methodologically comforted in maintaining a more narrow and limited understanding of the nature of social context by adopting methods which on the surface seem to 'get at' social context, but in truth remain on the 'outside' of meaning. Such studies fail to bridge the gap between text and context, by not examining more closely "how discourse and text 'index' social structure" (Starfield 2011: 176). The purpose of this chapter is to explore how indexes bridge the gap between a discipline's visible genres and its embodied knowledge and practices. Disciplinary newcomers are only able to participate fully in a discipline's activities by gaining access to all aspects of practice via its indexical system. To become proficient writers and participants in their discipline, students must thus learn about its indexes, in addition to the overt discoursal and linguistic patterns typically taught in the ESP/EAP and L2 writing classroom.