...
The zVariable QUALITY_BITMASK is set in the L1 CDF by the RPW data pipeline at LESIA and must not be changed by the RPW Calibration Software (RCS) when producing the L2 CDF. QUALITY_BITMASK bits allocated in L1 CDF must be saved "as is" in L2 CDF. To store information specific to L2 data, please use the dedicated L2_QUALITY_BITMASK CDF_UINT2 zVariable instead.
The optional CDF_UINT2 zVariable L2_QUALITY_BITMASK can be used instead in the RPW L2 CDF, in order to provide information related to the equipment. The name of this zVariable must be the same in all the L2 CDF, but the bit meaning can different.
...