Object.Rotation

MDT Description

This property changes the angle that an object is facing. The orientation of the map is that X goes to the right and Z goes up from the lower left corner. Y goes up. Your head is rotating in the XZ axis, the first parameter (aka yaw). Now imagine looking up, then down. Now your head is rotating in the YZ axis, the second parameter (aka pitch). Now, keep looking forward, but tilt your head to the left, then right. It is rotating in the XY axis, the last parameter (aka roll). The units used for this parameter are degrees (1 - 360) but you can have negative degrees as well. If you define multiple rotations, they happen in this order.

Object.Rotation H/P/B (Direction Of Nose):
(H/P/B have interchangeable degrees, i.e.: 90° = -270°)

H = 0° North | 90° East | 180° South | 270° West
H = 0° North | -270° East | -180° South | -90° West
P = 0° Forward | 90° Down | 180° Reverse | 270° Up
P = 0° Forward | -270° Down | -180° Reverse | -90° Up
B = 0° Upright | 90° On Left Side | 180° Upside down | 270° On Right Side
B = 0° Upright | -270° On Left Side | -180° Upside down | -90° On Right Side

Source and more details