2.1.784 Part 1 Section 18.10.1.70, pivotFields (PivotTable Fields)

a.   The standard does not specify a limit on the number of pivotField child elements.

In Office, if this PivotTable is an OLAP PivotTable, then the number of pivotField elements must be less than or equal to the number of cacheField elements on the associated cache. Otherwise they must be equal.