Data type: PtypInteger32 property ([MS-OXCDATA] section 2.11.1)

The PidTagDepth property ([MS-OXPROPS] section 2.664) specifies the number of nested categories in which a given row is contained. For example, if a row is contained within two header rows, its depth is 0x0002. When a table contains no categories, all rows will have a depth of 0x0000.