This is an inverse of the 'which computers have I authorized'
iTunes is fussing and refused to put some 30 apps back on my phone (mac had a hard disk crash. Restored from backup, but not clear that all the permissions are right.) I reentered all 3 authorizations, and got 'Already authorized' for two of them. This reduced the unloadable app count to 20.
Anyway, my wife and I between us have at least 3 apple IDs, one of which we have changed from the older 'arbitrary character string including spaces' to the 'use a valid email address' format.
The apps in question when I open iTunes go to apps, right click an app, and type 'get info' show the old format for the third id: "firstname lastname" Not the firstname.lastname@example.org.
On her computer the id shows up as "firstname lastname (email@example.com)"
I have authorized firstname.lastname@example.org and got the 'already authorized' message.
Q1. Where I can find out which apple id's are authorized on this computer?
Note I do NOT want to find out which comptuters this id is authorized on.