Supplemental recommendations.. help!

<p>I know that most schools require 2 teachers and 1 counselor, but if I want to have additional recommendation letters from a faculty adviser of a club, do i have to give her any forms or she just write a letter and send it off?</p>

<p>some colleges (princeton for example) have a form to use even if you are using the commonapp, but most schools are fine with a letter.</p>

<p>wait would the letter of the supplemental app be sent by mail and not via commonapp?</p>