| COMBINE_TYPE | int | Index to define the type input for the MasterFlat | | |
| DIG_FILTER_SIZE | float | Gaussian Fourier filter size | | |
| MAXIMUM_SUBWIN_DIFF | float | QC: Maximum sub-window difference between this flat and the previous version | | NUMR |
| MEDIAN_FILTER_SIZE | int | For cleaning bad pixels | | |
| MIRROR_XPIX | int | For mirroring edges (FFT continuity) | | |
| MIRROR_YPIX | int | For mirroring edges (FFT continuity) | | |
| SOURCE_CODE_VERSION | int | The version of the source code | | |
