privacy_policy_url, of type USVString
A link to the RP's Privacy Policy.
terms_of_service_url, of type USVString
A link to the RP's Terms of Service.
The client metadata structure allows for URLs to documents related to privacy policy and TOS. There is no affordance for performing language negotiation. These static links might be to documents for which it is important to have a translation available.
In addition, there doesn't appear to be a mechanism for negotiating language (locale) between the RP and IDP.
3.4 Client Metadata https://w3c-fedid.github.io/FedCM/#idp-api-client-id-metadata-endpoint
The client metadata structure allows for URLs to documents related to privacy policy and TOS. There is no affordance for performing language negotiation. These static links might be to documents for which it is important to have a translation available.
In addition, there doesn't appear to be a mechanism for negotiating language (locale) between the RP and IDP.