Table 1 Contents of DR10 Optical Imaging^a Total Unique^b Area imaged (deg^2) 31637 14555 Cataloged objects 1231051050 469053874 APOGEE spectroscopy Commiss. Survey Total Plate-visits 98 586 684 Plates 51 232 281 Pointings 43 150 170 Spectra Stars All stars^c 178397 57454 Commissioning stars 24943 11987 Survey stars 153454 47452 Stars with S/N > 100^d sdotsdotsdot 47675 Stars with >or=3 visits sdotsdotsdot 29701 Stars with >or=12 visits sdotsdotsdot 923 Stellar parameter standards 5178 1065 Radial velocity standards 162 16 Telluric line standards 24283 7003 Ancillary science program objects 8894 3344 BOSS spectroscopy Total Unique^b Spectroscopic effective area (deg^2) sdotsdotsdot 6373.2 Plates^e 1515 1489 Optical spectra observed^f 1507954 1391792 All galaxies 927844 859322 CMASS^g 612195 565631 LOWZ^g 224172 208933 All quasars 182009 166300 Main^h 159808 147242 Main, 2.15 < z < 3.5^i 114977 105489 Ancillary program spectra 72184 65494 Stars 159327 144968 Standard stars 30514 27003 Sky spectra 144503 138491 Unclassified spectra^j 101550 89003 All optical spectroscopy from SDSS up through DR10 Total spectra 3358200 Total useful spectra^k 3276914 Galaxies 1848851 Quasars 316125 Stars 736484 Sky 247549 Unclassified^j 138663 Notes. a These numbers are unchanged since DR8. b Removing all duplicates, overlaps, and repeat visits from the "total" column. c 2155 stars were observed both during the commissioning and survey phases. The co-added spectra are kept separate between these two phases. Thus the number of coadded spectra is greater than the number of unique stars observed. d Signal-to-noise ratio per half resolution element >100. e Twenty-six plates of the 1515 observed plates were re-plugged and re-observed for calibration purposes. Six of the 1489 unique plates are different drillings of the same set of objects. f This excludes the small fraction of the observations through fibers that are broken or that fell out of their holes after plugging. There were 1,515,000 spectra attempted. g "CMASS" and "LOWZ" refer to the two galaxy target categories used in BOSS (Ahn et al. 2012). They are both color-selected, with LOWZ galaxies in the redshift range 0.15 < z < 0.4, and CMASS galaxies in the range 0.4 < z < 0.8. h This counts only quasars that were targeted by the main quasar survey (Ross et al. 2012), and thus does not include those from ancillary programs (Dawson et al. 2013). i Quasars with redshifts in the range 2.15 < z < 3.5 provide the most signal in the BOSS spectra of the Lyalpha forest. j Non-sky spectra for which the automated redshift/classification pipeline (Bolton et al. 2012) gave no reliable classification, as indicated by the ZWARNING flag. k Spectra on good or marginal plates.