Most appear in places like Ask Ubuntu (and other Stack Exchange sites). I had not seen "official" information but I searched and found a blueprint:
https://blueprints.launchpad.net/ubuntu/+spec/deploy-dynamic-mirrors -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1813354 Title: release-upgrader unable to deal with sources.list entries of "deb mirror://" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1813354/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
