From the site:

  Years later I found out that my new knot was not new and that I had simply re-invented an existing knot, which appears elsewhere under two different names:

  “Double Slip Knot” (#1219) in “The Ashley Book of Knots” by Clifford Ashley;
  “Seaman's Shoelace Knot” (or “Seemännische Schuhbandschleife”), which appears in the German book “Knoten, Spleißen, Takeln” by Erich Sondheim.