The register ton is a unit of volume in the shipping world and uses the symbol GRT.
1 register ton is equal to 100 ft³ or 2.832 m³.
The register ton is used in shipping to measure the amount of cargo on a vessel. The phrase is often mistaken for a unit of mass or weight because of the term 'ton' but should not be confused.
The US liquid quart is a unit of volume in the US customary system with the symbol qt.
The US liquid quart is equal to 1/4 US liquid gallons, 2 US liquid pints, 4 US liquid cups, 8 US liquid gills or 32 US fluid ounces. The SI / metric equivalent is ≈ 0.946353 L.
The US liquid quart was based on exactly 57.75 in³ which was derived from the 1959 international yard and pound agreement whereby all traditional length and volume measures were legally standardised.