2.1.770 Part 1 Section 18.10.1.49, location (PivotTable Location)

a.   The standard does not bound the maximum allowed value on the firstHeaderRow attribute.

Office bounds the maximum allowed value of firstHeaderRow by the value of firstDataRow.

b.   The standard says the @ref specifies the first row of the PivotTable.

Office assumes that @ref specifies the range of the PivotTable excluding the page fields.