Manual Question, Chapt 9, page 9

First paragraph, right column says: "Additionally, in level flight, 30REF+100 provides minimum drag and best fuel economy for a non-cruise environment." Maybe this is a misprint or I'm missing something, but to me level flight is a cruise environment, regardless of time length. Or, if 30REF+30 is best drag/fuel ratio in level flight, then it is also the same in a cruise environment. ??Thankslouross.