Answer

When adding a field to your model, you have the option of 'allowing unmapped values to flow.'

If you do not allow unmapped values to flow (the default setting), the server will reject any value that is not specified in the model. In general, this is the recommended approach. If you select this approach, you will need to map all possible values for the repository field to the specific values for the model field during the Field Configuration step of configuring your integration.

If you do allow unmapped values to flow, field values not specified in the model will be able to flow while the integration is running. This can make sense in a few specific scenarios, such as an Enterprise Data Stream integration or in single select to string transforms, where there are many options available and you don't desire any normalization of the data flowing through. In most cases, however, you will not want to allow unmapped values to flow.

You can learn more in our User Guide here.