2.2.4.1 Master Identification
A master is specified by the combination of a Master_Type element in a Masters XML Part, and the ShapeSheet_Type elements in the Master XML Part specified by the Master_Type element’s Rel_Type child element. These ShapeSheet_Type elements are called master shapes.
The following elements in other parts of the document have attributes that reference masters.
A ShapeSheet_Type element in a Page XML Part can specify with its Master attribute the master it inherits from.
The Use function token accepts as its argument the name or GUID of a master.
The MasterSheetRef reference token references a master.