Note that the current documentation sheets are not updated to the latest versions of robot/URSim software (3.14 for CB and 5.9 for e-Series).
With those versions they introduced the matrix variable type and so the ValueTypes sheet shows wrong numeric values for type byte. According to my experiments I found these number-type correspondence:
3: string
12: pose
15: int
16: float
18: matrix
Try to experiment yourself to confirm these or to find out the others, until UR updates the sheets file.