Sea Water Salinity was used to be measured in g/kg, with values sometime written with the "‰" symbol (e.g. "35‰"). In modern oceanography, this has been replaced by Practical Salinity Unit (PSU), with values written without symbol (e.g. "35"). Strictly speaking, PSU units are not convertible to g/kg. However the PSU scale is by design very close to the old scale. If someone nevertheless attempts a conversion between those two scales, we want it to be close to the identity operation. Currently, the conversion wrongly multiply or divide values by 1000.