(47) 'A' → CS/α—β, where α'A'β is a σ, 'where, furthermore, σ is the category symbol that appears on the left in the rule σ → ...A... that introduces A'. Thus (47), reformulated within the framework of the theory of grammatical transformations, would be what we have called a 'local transformation'.
- Chomsky (1969), a pag.99

By a 'local transformation (with respect to A)' I mean one that affects only a substring dominated by the single category symbol 'A'.
- Chomsky (1969), a pag.215