British Sign Language has a number of regional variations. This article examines the role of residential schools in the development of sign variants. Citing data collected during interviews with members of the Lancaster and Morecambe Deaf community (who of necessity attended schools elsewhere), it explores the peer-to-peer transmission of sign forms in schools and the influence of these forms in the communities to which the pupils returned on leaving school (coining the term schoolization for this phenomenon). It discusses the effect the closure of such residential schools will have on the acquisition and transmission of BSL. (Contains 7 figures, 2 notes and 3 tables.)