No documentation for translation provider attribution requirements

The translation result (https://docs.joinmastodon.org/entities/Translation/) has a provider field (https://docs.joinmastodon.org/entities/Translation/#provider).

There is no Mastodon documentation I can find that explains whether Mastodon clients are supposed to show this information anywhere.

If I try translation from the web UI on mastodon.social translated statuses are shown with a footer, "Translated from Deutsch using DeepL.com".

That appears to be generated by the web app, as that text is not part of the API response.

I assume mastodon.social is using a DeepL Pro license. The public ToS for that says (https://www.deepl.com/en/pro-license?tab=pro, emphasis mine):

8.3.3 If the Customer provides an Application to Customer's End Users, the Customer must disclose to these End Users that any Processed Content displayed to the End Users without manual modification of Customer has been created using the API by either displaying the logo or the brand name (including the domain) of DeepL, unless expressly agreed upon otherwise. However, Customer must not express or imply that DeepL is responsible for the Processed Contents or that Customer acts on behalf of DeepL. Customer will cease any use of the DeepL logo and/or brand name on DeepL’s request.

As someone writing a client application that uses the API I don't know what agreements a given server might have w.r.t. disclosure with clauses like this.

Start with the Translation entity documentation and its provider field, then compare the web UI's attribution footer with the linked DeepL Pro license requirements. Confirm what client applications can document about server-specific translation agreements and provider attribution, and update the relevant API documentation with the resulting guidance.