Reference

Glossary

Plain definitions. Where a number matters, it lives on the linked page, not in this list.

Renewable diesel: A hydrocarbon diesel made from fats, oils, or other renewable feedstocks. In the United States it is the fuel that meets ASTM D975. It is not biodiesel. AFDC.
Biodiesel: A mono-alkyl ester made from vegetable oil, animal fat, or used cooking oil, used neat as B100 or as a blend stock that meets ASTM D6751. AFDC.
SAF: Sustainable aviation fuel, made from non-petroleum feedstocks and blended with conventional jet fuel within a pathway-specific limit. AFDC.
HEFA: The industry name for hydroprocessed esters and fatty acids. It is the hydrotreating route AFDC describes as the commercial way to make renewable diesel from fats, oils, and greases. AFDC.
RIN: A renewable identification number, the credit EPA attaches to a gallon of qualifying renewable fuel under the Renewable Fuel Standard. EPA.
D4: The D-code, in market shorthand, for a biomass-based diesel RIN. D3 is cellulosic, D5 is advanced biofuel, and D6 is renewable fuel. The code itself is defined in 40 CFR 80.1425.
D5: The D-code, in that same shorthand, for an advanced-biofuel RIN that is not cellulosic and not biomass-based diesel. See the RFS explainer.
D6: The D-code, in that same shorthand, for a renewable-fuel RIN, the broadest category, which conventional ethanol usually carries. See 40 CFR 80.1425.
RVO: Renewable volume obligation. The volume of renewable fuel an obligated party has to cover for a compliance year. EPA, Renewable Fuel Standard.
SRE: Small-refinery exemption. A waiver of an obligated party's renewable volume obligation. How EPA handled recent exemptions is in the RFS explainer.
Equivalence value: The number of RINs a gallon generates. EPA's rule for the 2026 and 2027 values is summarized, with the Federal Register link, on the RFS explainer. The application rule is 40 CFR 80.1415.
LCFS: California's Low Carbon Fuel Standard. Fuels below a yearly carbon-intensity benchmark earn credits. Fuels above it create deficits. CARB.
Carbon intensity: A lifecycle greenhouse-gas score. In the LCFS it is expressed as grams of carbon dioxide equivalent per megajoule. The benchmarks are in the LCFS explainer.
45Z: Section 45Z of the Internal Revenue Code, the clean fuel production credit for fuel produced in the United States. Explainer.
ULSD: Ultra-low sulfur diesel. The ticker's NYH ULSD quote is EIA's New York Harbor ultra-low sulfur No. 2 diesel spot price, in dollars per gallon. EIA series.
Spot price: A price for a physical commodity for prompt delivery, as distinct from a futures contract. The ticker uses EIA daily spot series and a World Bank monthly average. It does not use exchange futures. How the prices are read.