A lower transverse plane midway between the upper transverse and the upper border of the pubic symphysis; this is termed the intertubercular plane (or transtubercular), since it practically corresponds to that passing through the iliac tubercles; behind, its plane cuts the upper border of the fifth lumbar vertebra (L5).

This article incorporates text in the public domain from page 1315 of the 20th edition of Gray's Anatomy (1918)