<p>Totally aside from how it might look to colleges, how does it look to the person writing your recs? Think of your signature on the form as a courtesy to them, giving them your permission to speak freely. I frequently write letters for students. I never say anything bad, and I usually give the student a copy of the letter when it is finished. But I would have serious pause if a student refused to sign the waiver. If you do not trust the recommender enough to let them do it however they wish, then maybe you shouldn't be asking them for a letter.</p>