I think rule 11 is there simply to prevent the king from forcing a draw by camping next to the central square. The text of fig.1 is pretty clear; I can't imagine the phrase "no [other] person can be admitted" being used to mean "no [other] person can pass", with or without the "other". As I don't have access to the original Swedish, nor the knowledge to understand it, I don't feel in a position to doubt Smith's translation.