<p>But how are you supposed to know if it does or doesn’t if you can’t see the recommendation letters from your teachers?</p>
<p>You aren’t required to waive your right to view the recommendation letters. I remember there is a box that you have to check in order to waive those rights but I think it is optional.</p>
<p>It’s not an absolute rule – you just have to use your own best judgment. If two potential recommenders fill the same role in your life, teaching you in similar subjects or seeing you in similar extracurricular contexts, they are likely to write recommendations that touch on the same topics and stories. If two potential interviewers are from different aspects of your life, they are more likely to write letters exploring different parts of your persona. You’re not required to double-check that your letters say different things, just to exercise good judgment in choosing recommenders.</p>
<p>At any rate, it’s not that it isn’t allowed to have a supplemental recommendation that’s similar to one of your required recommendations. It’s just that it isn’t useful for the admissions officers, and therefore most likely isn’t helpful to you. It’s not detrimental, but it does mean you have lost the opportunity to tell the admissions office something new about yourself.</p>