Scaling relations for SCII galaxies. Line widths are measured from Hα rotation curves and disk scale lengths are measured using the marking the disk technique (see text). Luminosities are computed from fully corrected I‐band magnitudes. Unlike Dale et al. (1999), the luminosities do not include any correction for morphological type dependence. The solid black lines and reported slopes correspond the orthogonal fits to the combined data set. The point types and colors correspond to the Hubble classification from the authors (Dale et al. 1999).