The NSF funds ICERM, a Mathematics Institute based at Brown. Every semester, they bring 50 fellows to the campus; 40% come from overseas. WHile a fellow is here, they are provided with a Brown-issued identity and credential. When they return home, Brown deprovisions that credential, but ICERM wants the relationship to continue. ICERM wants an ex-fellow to use Federated access to login at their home campus in order to access services hosted here at Brown.
However, the home IDP (let's say its in the EU), before it releases any PII attributes, wants Assurances that the Brown SP will behave in accordance with the EU Privacy Directive.