This document outlines various commands that can be used via email to interact with the Meetin.gs platform. Some key functions include signing up for an account, setting up meetings from a calendar invitation, creating new meetings by email, inviting people to meetings, requesting more information about a meeting, adding materials and comments, and requesting to join a meeting. All interactions are done by replying to or sending emails to specific command addresses with the appropriate text in the subject or body to trigger the desired action in Meetin.gs.