College and Career Ready Standard 6.NS.4

My sixth-grade boy finished a math project he's proud of, a big poster that shows a lovely visualization of a prime factors. I checked its accuracy, not to mention its adherence to the Almighty Rubric—the only real way to answer the question of "is our children learning?"

His project was complete except for one of the listed instructions that seemed odd. I asked him about it. 

"Are you supposed to write this line on your poster?"

"I don't think so," he said. 

"That's what this rubric seems to say."

"But that's stupid."

"Very. But that's what it says." 

The instruction on the rubric said that for five points, the student must indicate that the project "Meets College and Career Ready Standard 6.NS.4."

"Ask your teacher tomorrow if you're honestly supposed to write that on your poster."

He came home the next day. "What was the answer?" "The answer was yes."

My son continued: "I asked if I could just forfeit the five points if I didn't write it. He said sure. But he also said that if I didn't write it then he wouldn't be able to post it on the wall."