Two consecutive DLAs in the SDSS J0148+1412 spectrum that both reveal narrow Lyα emission. A dashed (dash-dotted) red line marks the associated (intervening) DLA, and a solid yellow line indicates the velocity offset of the quasar. The spectral flux density in the associated DLA trough is clearly above zero, whereas the trough of the intervening system at Δv   ~  −22   800  kms^-1 goes to zero. No zero-level offset is applied in this figure.