2.1.1121 Part 1 Section 188.8.131.52, notesMaster (Notes Master)
a. The standard states that the notesMaster element specifies an instance of a handout master slide.
PowerPoint uses the notesMaster element to specify an instance of a notes master slide.
b. The standard does not specify the z-order of shapes in a notes master slide.
PowerPoint renders the shape elements contained in a notesMaster element in the order they are written. The note text is always rendered in the foreground.