- BDN
- Bunker Delivery Note — the document recording the quantity and characteristics of fuel delivered to a vessel.
- Bunkering
- The supply of fuel to a ship, whether by barge, truck or pipeline at berth or at anchorage.
- Cat fines
- Catalyst fines, abrasive particles carried over from refining that can cause engine wear if not removed by purification.
- Cutter stock
- A lighter component blended into residual fuel to bring viscosity and other parameters within specification.
- ECA
- Emission Control Area — a designated sea area with stricter sulphur or nitrogen oxide limits.
- HSFO
- High sulphur fuel oil, typically around 3.5% sulphur, used mainly by scrubber-fitted vessels.
- ISO 8217
- The international standard defining marine fuel specifications and test parameters.
- MGO
- Marine gasoil — a distillate marine fuel used where residual grades are unsuitable or unavailable.
- Off-spec
- Fuel that fails to meet the agreed specification on one or more parameters.
- Scrubber
- An exhaust gas cleaning system that allows a vessel to burn higher sulphur fuel while meeting emission limits.
- Stem
- A confirmed bunker order: the quantity, grade, port and delivery window agreed with a supplier.
- ULSFO
- Ultra low sulphur fuel oil at 0.10% sulphur, used inside emission control areas.
- VLSFO
- Very low sulphur fuel oil capped at 0.50% sulphur, the standard marine fuel for non-scrubber vessels.
- Viscosity
- A fuel's resistance to flow, which determines heating and handling requirements on board.
For market structure and pricing, see the fuel oil market guide, or follow our bunkering coverage.