Illustration of a fit to the Hα + [N II] λλ6548,6584 emission line complex for the host of SNF20060912-004, a typical moderate signal-to-noise case. The gray line shows the emission line spectrum of the local host. The grey band represents its uncertainty, centered around zero. The thick blue line shows the best posterior estimation. The thin blue lines represent 100 realizations from the posterior distribution, illustrating the fit uncertainties. A posterior density sampling in the Hα versus [N II] flux plane is displayed as an inset.