(this material was part of decision to use NetCDF3 for input files)
NetCDF data format
There are 5 variants of the format known as "netCDF": (See https://www.unidata.ucar.edu/software/netcdf/docs/faq.html#How-many-netCDF-formats-are-there-and-what-are-the-differences-among-them)
...