A uniaxial perpendicular magnetic anisotropy is perhaps one of the most important properties exhibited by thin film materials suitable for high-density magneto-optic recording disks. Previous works report studies of this anisotropy in amorphous rare earth-transition metal (RE-TM) alloys using measurements of the polar Kerr magneto-optic effect to provide the basic data. The experimental data so obtained is complementary to that usually provided by torque and VSM magnetometry but are sometimes difficult to analyse and not always unambiguous. The authors describe an examination of the data provided by the transverse Kerr magneto-optic effect in an attempt to provide further useful information concerning the nature of the anisotropy in magneto-optic recording materials.