Yeah, if I'm understanding it correctly, the word choice and communication really muddy the waters. If they chose to call it "unique identifier", and treat is a

Yeah, if I'm understanding it correctly, the word choice and communication really muddy the waters. If they chose to call it "unique identifier", and treat is a brand new value, I think there would be much less confusion and frustration. "Username" is too overloaded in this context for it to have been communicated clearly.