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 stere is a unit of volume and is a non-SI unit but accepted for use as a metric unit with the symbol st.
1 stere is equal to 1 cubic metre (1 m³) which is equivalent to the volume contained in a cube with edges all at 1 m. The stere is used to measure large quantities of cut wood or firewood. It is used to distinguish between cut and uncut wood - its equivalent, the cubic meter is used to measure uncut wood.
The word 'stere' hails from the Greek 'στερεός' or 'stereos' which translates to 'solid'. It represents the wood used to produce the cut wood - and therefore often the dimensions of the cut wood is less than its uncut equivalent.