2.1.1354 Part 4 Section 22.214.171.124, flatTx (No text in 3D scene)
a. The standard states that the flatTx element specifies the Z coordinate to be used in positioning the flat text within the 3D scene.
In Office, this element is used only when the text or shape is part of a 3D rotated group.
b. The standard states that the flatTx element is used to keep text out of a 3D scene.
In Office, the text will not be subjected to the 3D camera rotation, but will instead remain in a plane orthogonal to the viewing direction.