Note that the version number is contained within the netcdf file.
This fine contains:,
(1) the global data set of Absolute Salinity Anomaly Ratio,
(2) the global data set of Absolute Salinity Anomaly Ref.,
(3) a reference cast (for the isopycnal streamfunction),
(4) two reference casts that are used by gsw_demo
(5) three vertical profiles of (SP, t, p) at known long & lat, plus the outputs of all the GSW functions for these 3 profiles, and the required accuracy of all these outputs.