Flag definitions and categories

To help users interpret flag meanings, the following sections organize key flags into categories based on what the flag indicates. See also the Flag usage guidance for recommendations on the application of flags for scientific analyses.

This is not a complete list, and focuses on the most scientifically useful flags.

Pixel quality flags

Pattern: {band}_pixelFlags_*

Purpose: Report on issues with individual pixels in the source footprint, derived from image mask planes <images-mask-planes>.

Pixel quality flag	Tables	Meaning when set to 1
{band}_pixelFlags_{flagname}	Table1, Table2	Description here.

Measurement failure flags

Pattern: *_flag (algorithm-specific)

Purpose: Indicate that a particular measurement algorithm failed or produced unreliable results.

Measurement flag	Tables	Meaning when set to 1
{band}_{column}_flag	Table1, Table2	Description here.

DIA flags

Purpose: Indicate particular issues with difference image analysis (DIA).

DIA flag	Tables	Meaning when set to 1
{flagname}	Table1, Table2	Description here.

Special flags

Additional notable flags that provide ancillary information about source measurements.

Flag name	Tables	Meaning when set to 1
{flagname}	Table1, Table2, Table3	Description here.

Calibration flags

Pattern: {band}_calib_*

Purpose: These flags indicate whether a source was used in astrometric calibration, photometric calibration, or PSF modeling during single-visit processing.

For most science applications, these flags can be ignored as they pertain to internal use in the calibration process.

Calibration flag	Tables	Meaning when set to 1
{band}_calib_{flagname}	Table1, Table2	Description here.