This stroke is called: vertical hook.
"vertical hook" is pronounced shù wān gōu not u.
explanation of "vertical hook": vertical hook is one of the strokes of Chinese characters. In the application of calligraphy, it is named because its stroke shape resembles that of a goose floating on the water.
the writing method of "vertical hook": the left folding front of the reverse front slightly draws vertically downwards according to the stroke of the center, and the vertical drawing tends to be gradually lighter. At the corner, the center still turns slightly to the right with the wrist, and slightly presses the brush until the stroke reaches the hook, and the stroke hidden front is hooked upwards. The overall rhythm has, heavy and light changes.
Notes on the writing of "vertical hook":
The vertical part leans slightly to the left. The hook is upright, and the pen is pointed from heavy to light. In ancient times, calligraphers vividly called it a floating goose hook, just like a big goose, Xiang Tiange, floating on the water. The neck leans back, the belly bulges down, and the hook looks like the tail is up.
For example, the light in bold type is short, and many people are influenced by fine arts fonts such as bold type, so it is easy to write the bend short, which makes it appear rigid and long, while the standard regular script writing will make the hook longer for the sake of beautiful font.
The vertical hooks are not necessarily open, and even some of them are vertical hooks without hooks.