<?xml version='1.0'?>
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="portablectl" conditional='ENABLE_PORTABLED'
<listitem><para>btrfs subvolumes containing OS trees, similar to normal directory trees.</para></listitem>
<listitem><para>Binary "raw" disk images containing MBR or GPT partition tables and Linux file system
- partitions.</para></listitem>
+ partitions. (These must be regular files, with the <filename>.raw</filename> suffix.)</para></listitem>
</itemizedlist>
</refsect1>