diff --git a/data/example-preferences.xml b/data/example-preferences.xml
new file mode 100644
index 0000000..e054ef7
--- /dev/null
+++ b/data/example-preferences.xml
@@ -0,0 +1,27 @@
+<?xml version="1.0"?>
+<!DOCTYPE sgpem SYSTEM "preferences.dtd">
+<sgpem>
+    <recents>
+        <recent order="recent1" name="caio">Ultimo file aperto</recent>
+        <recent order="recent2" name="tullio">Penultimo file aperto</recent>
+        <recent order="recent3" name="sempronio">Terzultimo file aperto</recent>
+    </recents>
+    <layout>
+        <window id="mainwnd" geometry="0.0 0.0 100.0 100.0"/>
+        <window id="processeswnd" geometry="0.0 0.0 20.0 50.0"/>
+        <window id="resourceswnd" geometry="0.0 50.0 20.0 50.0"/>
+        <window id="schewnd" geometry="20.0 0.0 80.0 100.0"/>
+    </layout>
+    <preferences>
+        <default-speed>100</default-speed>
+        <modules>
+            <module id="python-sjf" />
+            <module id="python-rr" enabled="true" />
+            <module id="python-ocio" enabled="false" />
+        </modules>
+    </preferences>
+</sgpem>
+
+<!-- This file is for test only.
+     Handwrited to test DTD and for data example.
+     Validated with: xmllint  -->
\ No newline at end of file
diff --git a/data/preferences.dtd b/data/preferences.dtd
new file mode 100644
index 0000000..2086279
--- /dev/null
+++ b/data/preferences.dtd
@@ -0,0 +1,29 @@
+<!ELEMENT sgpem (recents, layout?, preferences) >
+<!ENTITY % text "#PCDATA">
+
+<!-- Ricorda i file piu' recenti -->
+<!ELEMENT recents (recent)*>
+<!ELEMENT recent (%text;)>
+<!ATTLIST recent 
+     order ID #REQUIRED
+     name CDATA #IMPLIED>
+
+<!ELEMENT layout (window)+>
+<!ELEMENT window EMPTY>
+<!-- 
+     attribute 'geometry' is: “x y width height”. All 
+     values are percentuals of the screen size 
+-->
+<!ATTLIST window
+     id ID #REQUIRED
+     geometry NMTOKENS #REQUIRED>
+
+<!-- Altre preferenze -->
+<!ELEMENT preferences (default-speed, modules)>
+<!ELEMENT default-speed (%text;)>
+<!ELEMENT modules (module)*>
+<!ELEMENT module EMPTY>
+<!ATTLIST module
+     id ID #REQUIRED
+     enabled (true | false) "false">
+