The orthodox legal position was re-stated namely, that where there is an effective reservation of title clause this does not constitute a conventional security device as it is a reservation of title by the supplier rather than a grant by the debtor of a jus in re aliena (see Chapter 12).

It may be that there is a special rule for reservation of title clauses: this is examined below (Chapter 10) but subject to that possible exception, once a contract has been made, its terms can only be altered or supplemented by a variation, and such variation will only be effective if it is supported by consideration.