Can be used when the switching rules in ISO 2859-1 are not applied. Indexing is by a preferred series of limiting qualities with a consumer's risk usually below 10 % and always below 13 %. Procedures are provided to cater for two situations: Procedure A to be used when the supplier and the consumer both wish to regard the lot in isolation (shall be used unless there is a specific instruction to use procedure B), procedure B to be used when the supplier regards the lot as one of continuing series but the consumer considers the lot received in isolation.