X6. Assessing the Suitability of New and Unusual or Non-Conventional Fuels or Blendstocks for Inclusion in Specification D975. Section 7.1 is proposed to be modified to return it to the form used for many years to describe the grades of diesel fuel oils included in D975. To allow inclusion of biodiesel in D975, the term hydrocarbon oils was changed to hydrocarbon based oils. Modifying 7.1 to hydrocarbon oils except as provided in 7.3 still allows inclusion of biodiesel and is felt to be less ambiguous. It also points to 7.3 as a place for non-hydrocarbon provisions in D975.