+<p><tt>setup</tt> will then ask you about authentication mode. <i>Please
+understand this question thoroughly before answering it.</i> You have a
+choice of two authentication modes:
+<ul>
+<li><i>Native authentication</i> - Citadel maintains its own user database.
+This is the normal mode of authentication. Citadel operates as a "black
+box" and your users do not have to have accounts or home directories on the
+host server.
+<li><i>Host based authentication</i> - access to Citadel is authenticated
+against the user database (<tt>/etc/passwd</tt> or perhaps NIS, etc.).
+</ul>
+You will be asked if you wish to use host based authentication. If you
+wish to do so, answer "Yes" at the prompt. For most installations, "No"
+is the appropriate answer.
+</p>