In Avi's YA novel Nothing but the Truth, Philip Malloy is a high school student who aspires to join to track team. However, he is thwarted from doing so after he gets a "D" in the English class taught by his self-proclaimed nemesis Miss Narwin—a grade that renders him ineligible for participating in the sport.

Out of childish anger, Philip decides that he will do whatever it takes to get himself removed from Miss Narwin's homeroom and English class. He spontaneously decides that the best way to do this is by humming loudly while the national anthem is played over the school loudspeaker in the mornings. This violates the rule the school has set forth that dictates that students behave respectfully while the anthem is played. Miss Narwin tells Philip to be quiet several times, but he refuses.

Eventually, Philip is kicked out of the class for creating a disturbance and sent to the office of the Assistant Principal, Dr. Joseph Palleni. Philip claims that Miss Narwin is against him being "patriotic" and exaggerates that he was "singing" not "humming," while Dr. Palleni argues that the rules can't be changed just for Philip. Dr. Palleni warns him that because this is his second violation of the rules, he is is risking suspension. He offers Philip an "out" from this punishment if Philip agrees to apologize to Miss Narwin and to follow the rules from this point forward.

However, Philip is stubborn and refuses to compromise. As a result, Dr. Palleni calls Philip's mother to inform her that her son has been given a two-day suspension and that she will need to come pick him up. During the meeting between Mrs. Malloy, Philip, and Dr. Palleni, Philip's mother asks if there's a rule against singing the national anthem. Dr. Palleni clarifies that the rule is against disturbing the class, and he asks Philip directly if he broke the rule. Rather than give an honest respond, Philip simply exclaims, "It's a dumb rule" (emphasis added).

So, in answer to your question, Philip describes the rule as "dumb." This conversation can be found in the section of the book labeled "10:42 AM: Conversation among Philip Malloy, Mrs. Malloy, and Dr. Joseph Palleni." In my copy of the book, this is on page 44—but keep in mind that various editions will have different page number corresponding to this section!