Absorption lines in the C IV region of the HST spectra of the SUBWAYS sample. For the remaining objects that are not displayed in this figure, no significant absorption line of any kind is seen in the C IV region. The ISM lines are labeled in blue, IGM lines in green, and the intrinsic AGN lines in magenta. The best-fit model to the AGN absorption lines is shown as a dotted magenta line. The significance σ is defined as (D−M)/E, where D is the data, M is the continuum+emission line model without absorption, and E is the error on the data.