In a Dialogue section of the "Journal of Sociolinguistics" (vol. 26, no. 1), author pairs introduce a number of themes and debates in sign language sociolinguistics, explore why these are debates; how the debates are situated within sociolinguistics as a whole; and how spoken language sociolinguistics does or does not have similar debates. In order to give authors room to think beyond established subject areas (such as "language contact" or "variationism"), five titles were chosen that foreground and represent debates rather than subject areas: Geographies and Circulations; Lumping and Splitting; Hierarchies and Constellations; Classifications and Typologies; Natural and Elicited. These main themes and debates in sign language sociolinguistics, as well as main parallels and differences with spoken language sociolinguistics, are introduced in this article.