2.1.1360 Part 4 Section 126.96.36.199, chOff (Child Offset)
a. The standard states that the child offset defined by the chOff element specifies the location of the child extents rectangle, which is used for calculations of grouping, scaling and rotating.
In Office, the child extents and offset are used to determine the center for scaling, rotation and flipping.
b. The standard states that the y attribute specifies a coordinate on the x-axis.
In Office, the y attribute specifies a coordinate on the y-axis.