Where the netCDF-2 interface used NF_LONG to identify an external data type corresponding to 32-bit integers, the new interface uses NF_INT instead. NF_LONG is defined to have the same value as NF_INT for backward compatibility, but it should not be used in new code. With new 64-bit platforms using long for 64-bit integers, we would like to reduce the confusion caused by this name clash. Note that there is still no netCDF external data type corresponding to 64-bit integers.