How to send in an additional Letter of rec?

<p>I have a letter of rec from a research mentor, but I'm not sure how to mail it in to Penn.</p>

<p>I called their office and I was told to attach the letter of rec to a "common application coversheet" that I should be able to get from the commonapp website. I could not find that sheet. </p>

<p>Has anyone else here successfully sent in a supplemental letter of recommendation that could tell me how to do this? Thanks!</p>

<p>Nobody has any idea? =&lt;/p>

<p>I’m not sure about a Common App cover sheet, but I mailed, in a large (ish) manilla envelope, the sealed recommendation and a cover letter. The additional rec was from my research mentor, and the cover sheet just stated my personal info (so they can add my rec to my file precisely), and who this recommender was (in 1-2 sentences). </p>

<p>I sent it to the Office of Undergrad. Admissions.</p>

<p>Thank you so much! This helps immensely =D</p>