<p>If I want to send a letter from a my research mentor, do I just assign him/her as an "Other Recommender" on the Common App? Or do I have to mail it in, as for Yale? I couldn't find anything on Harvard's website about this...</p>
<p>The Common Application is set up to be school specific. Yale allows for a 3rd recommendation, but Harvard does not, so your third letter should be snail-mailed into Harvard Admissions at 86 Brattle Street (and remember to include your birthdate and high school along with the letter).</p>
<p>^^ My bad, apologies to all. I just went to the Common App and checked. As @skieurope said, this year Harvard is allowing a 3rd recommendation letter, but Yale is not. It’s under MY COLLEGES ==> RECOMMENDERS AND FERPA. It looked like the below on my demo Common App.</p>
<p>No need to mail it in. I did that by clicking “add other recommender” and then entering in my person’s email and info. They get an email with a link to upload, and when they do it, it says “submitted.”</p>