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 gill is a unit of volume in the US customary unit system and uses the symbol gi.
It represents 1/4 of a pint - so in this instance, it is 1/4 of US pint - therefore measures exactly 118.29411825 ml. It's also equal to 8 tablespoons, 24 teaspoons and 5/6 imperial gills.
The gill has been mentioned a number of times in popular literature; including in Treasure Island, Animal Farm and in Dan Simmon's 'The Terror' - and all references are pointing to the use of the gill in terms of alcohol measures or servings.