HELP!! Art Supplement Letter of Rec

<p>I'm not sure if I'm going to do the art supplement anymore, but I already have a letter of rec for it. Can I use that as an additional letter of rec?
How will they know that the letter is for me and not somebody else with the same name as me?
Does UPenn even accept letters of rec beyond the required 2 teacher, 1 counselor?</p>

<p>I'm very confused.. HELP! >_<</p>

<p>add your soc sec # and common app #</p>

<p>So they WILL accept additional letters of rec if I decide NOT to use my art rec for the actual art supplement?</p>

<p>How do I find my common app #? @_@</p>