Standard vs. Helvetica in the New York City subway system: addendum no. 1

I was just perusing the 1970 New York City Transit Authority Graphic Standards Manual by Unimark when I noticed something odd. On p. 74, devoted not to station signage but to proposed train graphics, there is a discrepancy between the text discussing The Inside Line Map and the two diagrams illustrating it. The text reads, “For better distincition between type showing express stops and local stops we have chosen 48 pt. Standard medium and light˘ However, the diagrams—one showing the entire E line route and the other a detail where local and express stops are adjacent—are set in Helvetica medium and light!