One should be aware of the discrepancy in the magnitude of C dl of Pt(111) at the pzc, denoted 𝐶 dl,pzc , in different studies. 𝐶 dl,pzc is around 20 μF cm -2 in the study of Pajkossy and Kolb using an electrolyte concentration of 0.1 M, around 30 μF cm -2 in the study of Xue et al. with an electrolyte concentration of 0.05 M, and around 100 μF cm -2 in the study of Ojha et al. with an electrolyte concentration of 0.005 M. Note that 𝐶 dl,pzc shall decrease with the electrolyte concentration, according to the GCS model. Surprisingly enough, recent values of 𝐶 dl,pzc in more dilute electrolyte solutions are even several fold higher than previous values in more concentrated electrolyte solutions. This marked and surprising discrepancy might be ascribed to different methods used to determine C dl .