In the Veeam Service Provider Console REST API v3, some enums are marked with the x-extensible-enum: true extension. For those enums, new possible values may be added in further product updates.
To avoid future issues with your integration, you can instruct the server to return the unknown value instead of the values, that your client does not support. To do that, send the x-client-version header in each request. The value of the header is the version of the Veeam Service Provider Console REST API for which the integration is configured.
The current version of the Veeam Service Provider Console REST API v3 is 3.1.