auto stands for 'automatic', because such variables are automatically allocated for each function invocation. In C it became redundant because base types were a

auto stands for 'automatic', because such variables are automatically allocated for each function invocation. In C it became redundant because base types were added, and so the base type could start the definition (auto was still permitted with default base type of int until C99 I think). auto in B is a bit like 'let', it starts a declaration, along with 'extrn'.