In the writings that he formulated during this period, too, he imagined persons who were disabled –both physically challenged and mentally—as figures in need of renewed attention.[3] Although there is no evidence that Papanek met Koefoed, his influence pervaded the seminar where the original ISA was drafted. Charged with creating a sign-symbol to mark barrier-free accommodations, Koefoed presented an early version of the symbol at the July 1968 exhibition held at the SDO seminar's end. Koefoed's symbol depicts an empty wheelchair.