An argument passing convention where the actual argument is a variable V whose value is copied to a local variable L inside the called function or procedure. If the procedure modifies L, these changes will not affect V, which may also be in scope inside the procedure, until the procedure returns when the final value of L is copied to V. Under call-by-reference changes to L would affect V immediately. Used, for example, by BBC BASIC V on the Acorn Archimedes.