Abstract: "Since linguistic and anthropological study of sign languages began in the 1960s, most research has focused on national sign languages, with scant attention paid to indigenous and original sign languages. Vulnerable to extinction, the latter varieties can expand our understanding of language universals, language typologies, historical comparative linguistics, and other areas. Using Thailand as a case study and drawing on three examples – a rare phonological form, basic color terminology, and baby talk/motherese – from Ban Khor Sign Language, an indigenous signed code, this article describes the problem of benign neglect of sign languages in current discussions of language endangerment and argues for the importance of expanding such discussions to include codes expressed in the manual-visual channel."