http://i3xi5qxvbrngh3g6o7czwjfxwjzigook7zxzjmgwg5b7xnjcn5hzciad.onion/proposals/192-store-bridge-information.html
For some users, however, this option is not what they want: They might
use private bridges or have special security concerns, which would make
them want to connect to the IP addresses specified in their
configuration only, and not tell Tonga about the set of bridges they
know about, even through a Tor circuit. Also see
https://blog.torproject.org/blog/different-ways-use-bridge for more
information about the different types of bridge users.
Design:
Tor should provide a new configuration...