| 0x01 | HiZ | the object was targeted as a high-z quasar in SDSS. |
| 0x02 | LowZ | the object was targeted as a low-z quasar in SDSS. |
| 0x04 | Prim | the object is a primary target |
| 0x08 | Gen | the object was used to generate the NMF (non-negative matrix factorization) components |
| 0x10 | Nc | the number of components used was reduced compared to the number available |
| 0x20 | slc | a slope correction was applied |
| 0x40 | dip | an additional mask was applied to cover a dip in the reconstruction |
| 0x80 | man | the mask was defined manually |