2.1.109 Part 4 Section 22.214.171.124, object (Inline Embedded Object)
a. The standard states that any element from the VML namespace or the Office VML Drawing namespace is a valid child of the object element.
Word only allows the arc, curve, group, image, line, OLEObject, oval, polyline, rect, roundrect, shape, and shapetype elements from these namespaces to be children of the object element.
This note applies to the following products: 2007, 2007 SP1, 2007 SP2.