Even if the prompt is clear, the ask is a trap in and of itself. Because it's not possible to actually do, but it will induce an LLM to synthesize something that sounds right.

If it was not 'hidden', then everyone would ask about that requirement, likely in lecture, and everyone would figure out that they need to at least edit out that part of the requirements when using it as a prompt.

By being 'hidden', then most people won't notice it at all, and the few that do will fire off a one-off question to a TA or the professor in an email and be told "disregard that, it was a mistake, didn't notice it due to the font color" or something like that.