MDAC 2.5 SDK - OLE DB Programmer's Reference
Appendix C: OLE DB Properties
Property group: Rowset
Property set: DBPROPSET_ROWSET
Column? N
Type: VT_BOOL
Typical R/W: R
Description: IConvertType
The value of this property is read-only and is always set to VARIANT_TRUE, indicating that the rowset supports the specified interface. The value of this property cannot be set to VARIANT_FALSE. (This is also true of DBPROP_IAccessor, DBPROP_IColumnsInfo, DBPROP_IRowset, and DBPROP_IRowsetInfo.) If the consumer does not set the value of this property to true, the resulting rowset supports IConvertType.
Note Providers that support an interface must support the property associated with that interface with a value of VARIANT_TRUE. These properties are primarily used to request interfaces through ICommandProperties::SetProperties.