What is the meaning of "official star" in Feng Shui?

Feng shui used to be mostly used in yin houses. A good auspicious cave must be surrounded by mountains on the left, right and back, which can be protected. The word "concave wind" refers to the place where the three sides of the mountain are sunken or where two mountains intersect. The wind blowing from this sunken position is to keep out the wind, and the main response is different according to the direction of the concave wind. In the geomantic omen of modern houses, it is the most typical concave wind. It is two tall and close buildings with a narrow gap in the middle. When the wind blows from the other side of the two buildings, it passes through this narrow gap, forming a particularly nasty evil wind, that is, concave wind.