1.Musculoskeletal system diseases: Cervical spondylosis, neck muscle spasm, shoulder and back stiffness, stiff and painful neck, numbness in the elbow and arm;
2.Nervous system and mental disorders: Intercostal neuralgia, accessory nerve paralysis;
3.Other conditions: Pneumonia, common cold.

On the back, below the spinous process of the 2nd thoracic vertebra, 3 cun lateral to the midline. (This acupoint is bilateral, one on each side.)

Sure, I will translate the provided instructions into English.

Step 1: Sit up straight and lower your head;
Step 2: Identify the posterior median line: the vertical line made in the center of the back;
Step 3: On the posterior median line, you can see a prominent protrusion on the vertebrae at the junction of the neck and upper back;
Step 4: This protrusion is the spinous process of the 7th cervical vertebra, which can move with the neck's left and right rotation;
Step 5: Push down vertically from the spinous process of the 7th cervical vertebra for two vertebral spinous processes to reach the spinous process of the 2nd thoracic vertebra;
Step 6: Draw a horizontal line below the spinous process of the 2nd thoracic vertebra, and the point where this line intersects with the inner edge of the scapula is the location of this acupoint.