Transmission spectra for the NB dataset with 20 passbands spanning from 520 nm to 920 nm (top), the na i set covering the Na I doublet (bottom left), and the k i dataset covering the K I double (bottom right). The inner boxes correspond to the central 68% posterior intervals, the outer boxes to the central 99% posterior intervals, and Na I and K I lines are marked as black lines. The light grey line shows an Exo-Transmit spectrum with Na and K described in Sect. 7.2, the black dots show the Exo-Transmit spectrum binned to the dataset binning, and the slashed horizontal line shows the transmission spectrum mean.