[O i] λλ6300, 6364 lines from the fourth spectrum of PTF11mnb (+106 d, black line) as compared to the same lines in a late spectrum of SN 2005bf (from Modjaz et al. 2008, blue line). The [O i] λλ6300, 6364 lines are shown in velocity space and continuum subtracted, after fitting the continuum with a low order polynomial. The lines are fitted with the sum (solid curves) of two Gaussians (shown as dashed curved), with the same FWHM, relative flux ratio of 1:3, and peaks separated by 64 Å. The [O i] λ6300 line peaks are indicated with thick dashed lines, at −1640 km s^-1 for PTF11mnb and −2260 km s^-1 for SN 2005bf. The zero velocity of the line (at 6300 Å) is indicated with a solid, vertical black line.