These values are mutual exclusive, but they can be combined with VT_BYREF to specify being a value.
specifies the content type of the VARIANT object. Possible values are VT_UI1, VT_UI2, VT_UI4, VT_I1, VT_I2, VT_I4, VT_R4, VT_R8, VT_INT, VT_UINT, VT_BOOL, VT_ERROR, VT_CY, VT_DATE, VT_BSTR, VT_DECIMAL, VT_UNKNOWN, VT_DISPATCH and VT_VARIANT. These values are mutual exclusive, but they can be combined with VT_BYREF to specify being a value. If omitted, the type of value is used. Consult the msdn library for additional information.