| Category | str | Data product category: e.g. science frame or calibration frame | |
| FirstType | str | Data product type: e.g. Sky, Bias, Dark, Flat, Wave, Std | |
| SecondType | str | Data product type: e.g. Sky, Bias, Dark, Flat, Wave, Std | |
| Technique | str | Data product technique: e.g. image or spectrum | |
