Transverse collateral is several cun above ham which is at lateral aspect of thigh; it is a branch of small collateral which diverges from bladder meridian. The vessel is clear when impairs waist of weight lifting and can be treated by pricking out blood.

Transverse collateral starts from which meridian? According to the original context, transverse collateral stays sidewards several cun above cleft yang and position of staying sidewards is transverse collateral. Gaoshizong thinks it is belt vessel. Belt vessel is at waist and 2 cun phase contrasts here, so it is not belt vessel. The vessel should be lateral posterior aspect of thigh which is several cun above large intestine. Posterior aspect is areal area of bladder meridian and transverse collateral should pertain to branch of bladder meridian and run transversely to several cun above cleft.