Application developers can add custom information to the client dataset's Data property. Because this information is bundled with the data packet, it is included when you save the data to a file or stream. It is copied when you copy the data to another dataset. Optionally, it can be included with the Delta property so that a provider can read this information when it receives updates from the client dataset. 

To save application-specific information with the Data property, use the SetOptionalParam method. This method lets you store an OleVariant that contains the data under a specific name. 

To retrieve this application-specific information, use the GetOptionalParam method, passing in the name that was used when the information was stored.