During the rebel briefing on Home One before the attack on the second Death Star, Solo is asked if his strike team is assembled for the Tydirium shuttle and he seems somewhat confused that he is called a General (and so is Leia sitting next to him). Also there is a short conversation between Han and Lando a few moments back during which Han notices Lando's promotion to a General but nothing is ever said of he himself being a General as well.
Since the first time I watched this movie, I've always thought that Han didn't really know his rank (and he is not wearing a badge or uniform) within the Alliance.
Is there any canon reference to support or dismiss this idea?