The Visual Basic Upgrade Companion can be extended so that the VB Upgrade Wizard’s core functionality is customized to satisfy your specific VB6 migration needs. New extensions augment the translation dictionary by adding new transformation rules and custom mappings, or even overriding the standard mappings.
For example, the mappings included in the Visual Basic Upgrade Companion to upgrade ADO to ADO.NET are added using extensibility. This mechanism allows programmers to decide whether they want to upgrade using these new rules or not. In case that they do not want to upgrade to ADO.NET, they only need to modify the extensibility configuration file and remove the corresponding ADO.NET entry.
Example: No mappings or extensions, so ADO is not upgraded
Example: Upgrade to ADO.NET by adding extensions or custom mappings