In order to identify an individual, participants and analysts must interpret signs uttered or displayed by that individual, or signs uttered or displayed by others with respect to that individual. At the moment of utterance or display, however, participants and analysts often do not know what context is relevant for interpreting a sign of identity. We can interpret signs of identity only as they get recontextualized by subsequent discourse (Garfinkel & Sacks, 1970; Goffman, 1976; Silverstein, 1992). Although there are of course many formulaic, predictable interactions, participants and analysts can generally identify an individual only over time, as a pattern of mutually-presupposing indexical signs comes to establish that the sign of identity in question did in fact have a determinate meaning (Silverstein, 1998; Wortham, 2001a).