Let visitors take part

Visitors have no write access, and they still sign the guestbook, vote in the poll, reply in the conversation and tick the steps of this course. Every one of those goes through RPC v1: the server checks who they are and writes on their behalf, under the identity it stamped.

Nobody signs up, nobody signs in, and nobody can act as somebody else. That is the shape of this platform's access model applied to a comment box.