Features of interpersonally perceivable communicative conduct, including speech, function as indexical signs insofar as they point to or delineate features of their contextual surround; they function as social indexicals when what they delineate are aspects of the social roles or relationships performed by interactants or the social practices in which interactants are engaged; and they function as stereotypic social indexicals when many persons construe them in comparable ways. Enregisterment is the sociohistorical process through which stereotypic social indexicals are differentiated from each other and organized into socially distributed registers of communication. A register is identified by attending to the metapragmatic behaviors of its users, behaviors that typify the pragmatic or indexical values of its signs. To identify a register is to characterize three variables—its exponents, its social range, and its social domain—and their values or attributes: The exponents of a register are the perceivable behaviors through which it is performed, whose semiotic range may include speech and non-speech signs arrayed into co-occurrence styles, where speech segments may involve discrete repertoires, and where performed exponents serve as diacritics that differentiate the register from others. The social range of a register is the range of social indexical effects performable through its use—whether usage is emblematic of social categories of speaker-actor (viz., class, gender, caste, profession, etc.), of relationships to interactants, or of the social practices such usage makes palpable or sustains. The social domain of a register is the group of persons acquainted with the register, those able to perform or construe the effects enactable through it. All speakers of a language do not acquire competence in all its speech registers during the normal course of language socialization. Asymmetries of socialization link contrasts among registers to features of social organization, such as facts of positional ranking within society, the ability to take part in specific social practices, opportunities within a division of labor, and the myriad forms of exclusion or belonging that emerge as outcomes of such processes.