Should OIDC subs be globally unique?

[Alan Buxey]

hi,

If a relying party consumes identities from multiple operators, then
it must combine the sub and iss claim to create a globally unique
identifier. ie scoping isnt in the role of the Identity Provider
(their role is just to ensure the subs are unique and don't change :).
- obviously this brings into play issues such as what happens
if/(when!) the ISS changes.....

alan