2.1.1283 Part 1 Section 20.1.7.6, xfrm (2D Transform for Individual Objects)

a.   The standard states that the rot attribute specifies the rotation of a graphic frame.

In Office, rot specifies the clockwise rotation of a shape.

b.   The standard allows attributes flipH, flipV and rot to be applied to a graphicFrame.

In Office, attributes FlipH, flipV and rot are ignored when applied to a graphicFrame.