2.1.1294 Part 1 Section, gradFill (Gradient Fill)

a.   The standard states that the flip (Tile flip) attribute specifies the direction(s) in which to flip the gradient while tiling.

In Office the flip (Tile flip) attribute is ignored and flip mode xy is used.

b.   The standard states that a gradient fill encompasses the entire bounding box of the shape that contains the fill.

In Office, a gradient fill encompasses a region larger than the bounding box of a shape when the shape contains arrowheads.