pEW₅₀₁₈ as a function of the SN phase. Filled symbols label our (i)PTF SNe II. Most of them are SNe IIP, and those circled in black are SNe IIL (i.e., they show a decline rate >0.014 mag d^-1 on the plateau). The spectral models by D14 indicating different Z are represented by solid lines. Our SNe are subgrouped and color-coded in 4 subsets based on the pEW(t) model to which they appear closest. pEW measurements from D14 and Anderson et al. (2015a) are shown by empty circles (gray and blue, respectively). Our SN sample includes a subset of objects with unprecedentedly small pEW, consistent with Z_SN = 0.1 Z_⊙. The only object with similar pEW(Fe ii 5018) is LSQ13fn (Polshaw et al. 2016).