|Y needs one more decorative stroke.|
Redoubled Gothic adds a little more ornament compared with yesterday's Doubled Gothic (left); two little strokes overlap the left stroke of half of the letters (except U and Y with the strokes inside, Z and W with the internal dash, and A C E G O Q S T V X with no extra strokes).
There are in fact at least three kinds of small strokes that can be added: square, parallelogram, curve. And three are three ways to add them: float (not shown), touch, overlap. The diagram at right comes from the Gothic capitals chapter in Learn Calligraphy.