A user can view or revoke their agreement at any time. On revoking, they are logged out and can only use the system again if they agree to the terms when they try to log in.
As an administrator you can:
format the terms as you wish with HTML
edit the terms whenever you need to
select individual users or Confluence groups to be notified whenever a user revokes their agreement
see which users have accepted the terms and when they gave their agreement