| 1 | HIZQSO82 \sep Quasar candidate in SDSS stripe 82 selected with UKIDSS YJHK photometry using a more relaxed color cut |
| 2 | HIZQSOIR \sep Quasar candidate selected with UKIDSS YJHK photometry |
| 4 | KQSO_BOSS \sep Quasar candidate selected with UKIDSS YJHK photometry |
| 8 | QSO_VAR \sep Candidate quasar in Stripe 82 survey area, selected from variability alone |
| 16 | QSO_VAR_FPG \sep Candidate quasar in Stripe 82 survey area, selected from variability alone |
| 32 | RADIO_2LOBE_QSO \sep Object near the midpoint of a double-lobed object identified in FIRST Catalogs |
| 64 | STRIPE82BCG \sep The brightest cluster member of a galaxy cluster or group identified in the Stripe 82 survey area |
| 128 | QSO_SUPPZ \sep A subset of SDSS-I/-II quasars with 1.8 < z < 2.15 that were reobserved with the BOSS spectrograph to measure metal absorption free of any effects from the Lyman-α forest (no longer used in DR12) |
| 256 | QSO_VAR_SDSS \sep Quasars selected by photometric variability in the overlap regions between stripes of SDSS-I/-II imaging, accounting for roughly 30% of the total BOSS footprint (no longer used in DR12) |
| 512 | QSO_WISE_SUPP \sep Quasar targets selected on their mid-infrared colors from the WISE satellite, thought to be z>2.2 quasars, as a supplement to the primary BOSS quasar sample (no longer used in DR12) |
| 1024 | QSO_WISE_FULL_SKY \sep Quasar selected from the WISE All-Sky Survey |
| 2048 | XMMSDSS \sep Hard x-ray-selected AGN from XMM |
| 4096 | IAMASERS \sep Known or potential maser |
| 8192 | DISKEMITTER_REPEAT \sep Candidate massive binary black hole pair |
| 16384 | WISE_BOSS_QSO \sep Quasar identified in the WISE All-Sky Survey |
| 32768 | QSO_XD_KDE_PAIR \sep Candidate closely-separated quasar pair |
| 65536 | CLUSTER_MEMBER \sep Member of a galaxy cluster selected from ROSAT All-Sky Survey data |
| 131072 | SPOKE2 \sep Candidate binary pair in which one star is an M dwarf |
| 262144 | FAINT_ELG \sep Blue star-forming galaxy selected from CFHT-LS photometry |
| 524288 | PTF_GAL \sep A nearby galaxy identified in PTF imaging with an SDSS counterpart |
| 1048576 | QSO_STD \sep A standard star targeted to improve BOSS spectrophotometric calibration |
| 2097152 | HIZ_LRG \sep A candidate z > 0.6 LRG, selected using a narrower r-i color constraint and observed at higher priority |
| 4194304 | LRG_ROUND3 \sep A candidate z > 0.6 LRG, selected using a broader r-i color constraint and observed at lower priority |
| 8388608 | WISE_COMPLETE \sep Galaxy in the same redshift range as the BOSS CMASS sample, but selected with a more relaxed color cut |
| 16777216 | TDSS_PILOT \sep Objects identified from PanSTARRS imaging using the selection criteria described on the BOSS ancillary target page |
| 33554432 | SPIDERS_PILOT \sep Objects identified from PanSTARRS imaging using the selection criteria described on the BOSS ancillary target page |
| 67108864 | TDSS_SPIDERS_PILOT \sep Objects identified using both sets of selection criteria for TDSS_PILOT and SPIDERS_PILOT |
| 134217728 | QSO_VAR_LF \sep Candidate quasar in stripe 82, selected by color and variability |
| 268435456 | TDSS_PILOT_PM \sep Objects identified using X-ray imaging that has high proper motions |
| 536870912 | TDSS_PILOT_SNHOST \sep Objects identified in PanSTARRS imaging that showed transient behavior in extended objects |
| 1073741824 | FAINT_HIZ_LRG \sep Candidate galaxy in the redshift range 0.6 < z < 0.9, defined by color cuts |
| 2147483648 | QSO_EBOSS_W3_ADM \sep Candidate quasar, defined by one of the complex color cuts described below and recorded in the W3bitmask parameter of the original targeting file |
| 4294967296 | XMM_PRIME \sep Candidate AGN identified from the XMM-XXL survey observed at higher priority |
| 8589934592 | XMM_SECOND \sep Candidate AGN identified from the XMM-XXL survey observed at lower priority |
| 17179869184 | SEQUELS_ELG \sep Emission-line galaxy targeted by the SEQUELS program |
| 34359738368 | GES \sep Star observed by the Gaia/ESO Survey (GES) |
| 68719476736 | SEGUE1 \sep Star observed by the prior SDSS spectroscopic SEGUE-1 survey |
| 137438953472 | SEGUE2 \sep Star observed by SEGUE-2 |
| 274877906944 | SDSSFILLER \sep Star in the GES survey area, targeted from prior SDSS photometry |
| 549755813888 | SEQUELS_ELG_LOWP \sep Emission-line galaxy targeted by the SEQUELS program at lower priority |
| 1099511627776 | 25_ORI_WISE \sep WISE-selected target near the star 25 Ori |
| 2199023255552 | 25_ORI_WISE_W3 \sep WISE-selected target near the star 25 Ori, selected from data in the W3 band |
| 4398046511104 | KOEKAP_STAR \sep WISE-selected source in the star-forming region Kappa Ori, selected from WISE infrared excess |
| 8796093022208 | KOE2023_STAR \sep WISE-selected source in the star-forming region NGC 2023, selected from WISE infrared excess |
| 17592186044416 | KOE2068_STAR \sep WISE-selected source in the star-forming region NGC 2068, selected from WISE infrared excess |
| 35184372088832 | KOE2023BSTAR \sep Other WISE-selected source in the star-forming region NGC 2023 |
| 70368744177664 | KOE2068BSTAR \sep Other WISE-selected source in the star-forming region NGC 2068 |
| 140737488355328 | KOEKAPAPBSTAR \sep Other WISE-selected source in the star-forming region Kappa Ori |
| 281474976710656 | COROTGESAPOG \sep Star observed by both the CoRoT survey and by APOGEE |
| 562949953421312 | COROTGES \sep Star observed by both CoRoT and GES |
| 1125899906842624 | APOGEE \sep Star in the CoRoT survey area, not observed by CoRoT but with an APOGEE spectrum |
| 2251799813685248 | 2MASSFILL \sep Star in the CoRoT survey area targeted from 2MASS photometry |
| 4503599627370496 | TAU_STAR \sep Spitzer-selected source in the Taurus Heiles 2 molecular cloud |
| 9007199254740992 | SEQUELS_TARGET \sep A target from the SEQUELS program (no longer used, replaced by EBOSS_TARGET0 flag) |
| 18014398509481984 | RM_TILE1 \sep AGN selected for reverberation mapping study at high priority |
| 36028797018963968 | RM_TILE2 \sep AGN selected for reverberation mapping study at lower priority |
| 72057594037927936 | QSO_DEEP \sep Candidate quasar selected by time variability |
| 144115188075855872 | LBG \sep Candidate Lyman-break galaxy selected by color |
| 288230376151711744 | ELAIS_N1_LOFAR \sep LOFAR source selected with RMS noise criteria |
| 576460752303423488 | ELAIS_N1_FIRST \sep Source detected in the FIRST radio catalog |
| 1152921504606846976 | ELAIS_N1_GMRT_GARN \sep Source identified from deeper GMRT radio data |
| 2305843009213693952 | ELAIS_N1_GMRT_TAYLOR \sep Fainter source identified from deeper GMRT radio data |
| 4611686018427387904 | ELAIS_N1_JVLA \sep Very faint source detected in JVLA radio data |
| 9223372036854775808 |