difference between &#39;assigned&#39; and &#39;endorsed&#39; in this context?
<blockquote>
  <p>Each such notice of redemption shall be irrevocable and shall specify
  the date that is the redemption date, the redemption price, the number
  of Shares to be redeemed, the place or places of payment and that
  payment will be made upon presentation and, to the extent that such
  Shares are certificated, surrender of the certificate(s) evidencing
  the Shares of Series B Preferred Stock to be redeemed (properly
  <strong><em>endorsed</em></strong> or <strong><em>assigned</em></strong> for transfer, if the Corporation shall so
  require).</p>
</blockquote>

<p>I know the basic meanings of both words. However, as a non-native speaker, I fear there might be some specialized nuance here that I can't seem to grasp.</p>

<p>"Endorsement" in this case refers to the concept of negotiation. If a negotiable document with one owner (such as a check or promissory note or negotiable bond or stock certificate) is signed (i.e. "endorsed") in the proper place on the original document by that owner, then the person who is in physical possession of the endorsed document (the "holder" of the endorsed document) is now its true owner. There is a body of statutory and case law setting forth which documents may and may not be negotiated in this manner (in the United States, this is located mostly in the Uniform Commercial Code). </p>

<p>If the endorsement is made on a separate piece of paper attached to the negotiable document it is called an "<a href="https://en.wikipedia.org/wiki/Allonge" rel="nofollow noreferrer">allonge</a>", and it could fairly be called either an endorsement or an assignment.</p>

<p>An "assignment" would be a transfer of ownership concluded in some manner other than negotiation of the original document by endorsing it, for example, by a bill of sale document signed by the owner declaring that the new owner is the person who is now presenting the stock.</p>

corporate-law legal-terms shareholders