Are you sure?
https://developer.hashicorp.com/vault/docs/what-is-vault has a "Edit this page on GitHub" link at the bottom which leads to https://github.com/hashicorp/vault/blob/main/website/content/docs/.

One would need to properly check, but if the website and docs were under the same license as the rest of the project, up until hashicorp/vault#22290 on the 11th of August, the docs would fall under the MPL license, meaning the version of the docs at that time could be imported into the OpenBao project.

As usual, IANAL and IANYL etc.

@axelsimon Yes, that link is for the documentation which is contained under our website folder. @JanMa has already done a lot of great work on forking and updating that :-)

Check out this link instead: https://developer.hashicorp.com/vault/tutorials/secrets-management/pki-engine

(see /tutorials/ in the URL versus /docs/)

This was in a different (internal) repo and don't have an Edit on GitHub link, e.g., hashicorp/vault#22761 which discusses this... These tutorials don't have a license associated with them and so likely would have to be rewritten.

Ah, i see. Thanks for taking the time to clarify!
Indeed, if there is no license associated, then plain copyright applies.