A Civil Air Patrol peculiarity...

CAP often throws around the term "grade" when what they are really referring to is "rank". The term grade refers to a pay grade. For example, I'm an E-7 [pay grade] in the California State Guard, which tells personnel folks that, when on those rare occasions that I do get paid, I make more than a staff sergeant but less than a master sergeant, because my rank is that of a sergeant first class. - 1st Lt Vallee

(So at the rank of first lieutenant, my [pay] grade would be O-2.)