Search Companies API - missing documentation for restrictions enumeration

We are using your companies search API.

https://developer-specs.company-information.service.gov.uk/companies-house-public-data-api/reference/search/search-companies

The ‘restrictions’ enumeration does not seem documented on the website. There are a couple of example values but not a full list.

Is it possible for details on this ‘restrictions’ enumeration to be provided?

Thanks,
Paul