Si, number four; feng, crevice. The point is located on the ulnar palmar aspect of the index, middle, ring and little fingers. Four points on each hand. So, it was called "Sifeng".
Four points on each hand, on the palmar side of the 2nd to 5th fingers and al the centre of the proximal interphalangeal joints.
Infantile malnutrition, pertussis.
Prick to cause bleeding, or squeeze out a small amount of yellowish viscous fluid locally.