Related to clause 8.10 of the Federation Rules
The most common example is when a research staff member leaves one university and another but still needs to (and is authorised to) access data, computing grids, instruments, or services they used previously. The auEduPersonSharedToken is the unique, persistent identifier that tells these services it’s the same person as before. It’s also possible for one person to be working at more then one university at the same time and to use the same auEduPersonSharedToken at both. The request would need to be initiated by the user, as they would be the only one to know they had joined a new university. It would involve an administrative verification process between the two universities which could simply be paper based.