http://tzoz3bensgxyzs7da7lpgsn3a74h7hlbm4wa6ytq2tg6ktd57w22vqqd.onion/doc/about/openpgp_keys/signing_key_revocation/index.en.html
Keeping the members of the groups B, C, and D up-to-date At least every 2 years, we make sure that the mechanism still works: We review internally the list of members of each group and decide
possible additions to, and removals from, each group. We write to every individual member of each group to ask them to check
that they still have their share and the number in the file name.