[DISPLAY\]SET FORMAT DataFormat [Specifier] List or specify the default data format for the WRITE command. Allowed val- ues are FITS or GILDAS. For FITS format, the additional Specifier can be NATIVE, VELOCITY or FREQUENCY to indicate the unit of the spectral axis. The default is NATIVE, namely taking the current spectral axis type, if not specified. The data format can be overidden by arguments of the command WRITE.