To create a fully featured application settings provider that supports application versioning, the provider must implement the System.Configuration.IApplicationSettingsProvider interface. One of the members in this interface, the IApplicationSettingsProvider.Upgrade(SettingsContext, SettingsPropertyCollection) method, is called to notify the provider that a new version of the application has been installed. In response, the provider is expected to perform an appropriate action, typically migrating past application settings.

The System.Configuration.NoSettingsVersionUpgradeAttribute informs the provider to suppress the upgrade logic associated with the current settings class. Therefore, the value of the previous version of this property group should not be migrated to the new installation.