We can find the answer to this question in act 2, scene 1, which opens with Polonius briefing Reynaldo on his mission in Paris. Polonius tells Reynaldo to "inquire me first what Danskers are in Paris" and what company they keep, knowing that Reynaldo will soon discover through these inquiries that "they know [his] son," Laertes. Having ascertained this, Reynaldo is tasked to then claim "some distant knowledge" of Laertes, such as that Reynaldo is a friend of the family but not close to Laertes personally.

Polonius then wants Reynaldo to "put on [Laertes] what forgeries" he pleases—that is, to tell those he meets in Paris that Laertes is given to "wild and unusual slips," not sufficient statements to completely ruin his reputation but enough to suggest that he is a "wild" youth. Polonius gives some suggestions of what to cite, such as "drinking, fencing, swearing, quarrelling." These would all be completely untrue rumors, but having spread them, Polonius feels the people who know Laertes in Paris would be more inclined to tell their own stories in return about what Laertes is actually doing there.