Index: head/en_US.ISO8859-1/books/handbook/jails/chapter.xml
===================================================================
--- head/en_US.ISO8859-1/books/handbook/jails/chapter.xml
+++ head/en_US.ISO8859-1/books/handbook/jails/chapter.xml
@@ -535,8 +535,33 @@
 	to maintain jails instead.  Use <option>-b</option> to specify
 	the path of the jail to be updated.</para>
 
+      <para>To update the jail to the latest patch release of the
+	version of &os; it is already running, then execute the
+	following commands on the host:</para>
+
       <screen>&prompt.root; <userinput>freebsd-update -b <replaceable>/here/is/the/jail</replaceable> fetch</userinput>
 &prompt.root; <userinput>freebsd-update -b <replaceable>/here/is/the/jail</replaceable> install</userinput></screen>
+
+      <para>To upgrade the jail to a new major or minor version,
+	first upgrade the host system as described in
+	<xref linkend="freebsdupdate-upgrade" />. Once the host has been
+	upgraded and rebooted, the jail can then be upgraded.
+	For example to upgrade from 12.0-RELEASE to 12.1-RELEASE,
+	on the host run:</para>
+
+      <screen>&prompt.root; <userinput>freebsd-update -b <replaceable>/here/is/the/jail</replaceable> --currently-running <replaceable>12.0-RELEASE</replaceable> -r <replaceable>12.1-RELEASE</replaceable> upgrade</userinput>
+&prompt.root; <userinput>freebsd-update -b <replaceable>/here/is/the/jail</replaceable> install</userinput>
+&prompt.root; <userinput>service jail restart <replaceable>myjail</replaceable></userinput>
+&prompt.root; <userinput>freebsd-update -b <replaceable>/here/is/the/jail</replaceable> install</userinput></screen>
+
+      <para>Then, if it was a major version upgrade, reinstall all
+	installed packages and restart the jail again.  This is
+	required because the ABI version changes when upgrading
+	between major versions of &os;. From the host:</para>
+
+      <screen>&prompt.root; <userinput>pkg -j <replaceable>myjail</replaceable> upgrade -f</userinput>
+&prompt.root; <userinput>service jail restart <replaceable>myjail</replaceable></userinput></screen>
+
     </sect2>
   </sect1>