The drawing indicates the position of the inscribed blocks and busts as Herzfeld found them (it leaves out other features, such as uninscribed blocks). The red rectangles indicate blocks with the Parthian version of inscription; the black rectangles the blocks with the Persian version.
Herzfeld, Ernst. 1924. Paikuli: Monument and Inscription of the Early History of the Sasanian Empire. Berlin: D. Reimer & E. Vohsen. Fig. 1.