diff --git a/debian/var/models/XML model example (in progress) b/debian/var/models/XML model example (in progress)
index 1e1fda3..92cc323 100644
--- a/debian/var/models/XML model example (in progress)	
+++ b/debian/var/models/XML model example (in progress)	
@@ -1,27 +1,34 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <gem-graph-model>
+
     <identity>
-       <model_name>Modèle de test</model_name>
+       <anything_but_not_just_the_word_name>Modèle de test</anything_but_not_just_the_word_name>
        <name value="(Trois dimères)"/>
        <owner_id>2</owner_id>
        <date>1629830000</date>
        <version>1.0</version>
     </identity>
+
     <parameters id="0" date="0" author="Gaston Lagaffe">
-       <modelization>
-           <max_thread value="0"/>
-           <max_cycles value="13"/>
-       </modelization>
-       <space>
+
+        <modelization>
+            <max_thread value="0"/>
+            <max_cycles value="13"/>
+        </modelization>
+
+        <space>
             <dimension value="1"/>
             <size value="39"/>
             <site_multiplicity value="2"/>
             <boundaries/>
-       </space>
+        </space>
+
     </parameters>
+
     <objects id="dimer" date="1629830000" author="Jean Sirmai">
         <arrow x="0" y="0" z="0" site="0" weight="0"/>
     </objects>
+
     <space>aaa</space>
     <savestates>aaa</savestates>
     <transitions>aaa</transitions>
diff --git a/debian/var/models/XMLSchema example (in progress) b/debian/var/models/XMLSchema example (in progress)
index ad31fcc..f0c4733 100644
--- a/debian/var/models/XMLSchema example (in progress)	
+++ b/debian/var/models/XMLSchema example (in progress)	
@@ -1,6 +1,23 @@
 <?xml version="1.0"?>
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
 
+<!-- https://www.w3schools.com/xml/el_attribute.asp  -->
+<!-- use="required" should be allowed ?!-->
+
+<xs:attribute name="id" type="xs:string"/>
+<xs:attribute name="date" type="xs:integer"/>  <!--TODO  type ? -->
+<xs:attribute name="name" type="xs:string"/>   <!--TODO  pas clair, ce truc... -->
+<xs:attribute name="value" type="xs:integer"/> <!--TODO  WARNING: It's an integer !-->
+<xs:attribute name="author" type="xs:string"/>
+<xs:attribute name="version" type="xs:float"/>
+<xs:attribute name="owner_id" type="xs:integer"/>
+
+<xs:attribute name="x"  type="xs:integer"/>
+<xs:attribute name="y"  type="xs:integer"/>
+<xs:attribute name="z"  type="xs:integer"/>
+<xs:attribute name="site"  type="xs:integer"/>
+<xs:attribute name="weight"  type="xs:integer"/>
+
 <xs:element name="gem-graph-model">
 <xs:complexType>
 <xs:sequence>
@@ -9,13 +26,13 @@
         <xs:complexType>
         <xs:sequence>
 
-            <xs:element name="model_name" type="xs:string"/>
+            <xs:element name="anything_but_not_just_the_word_name" type="xs:string"/>
 
-                <xs:element name="name">
-                    <xs:complexType>
-                        <xs:attribute name="value"  type="xs:string"/>
-                    </xs:complexType>
-                </xs:element>
+            <xs:element name="name">
+                <xs:complexType>
+                    <xs:attribute name="value"  type="xs:string"/>
+                </xs:complexType>
+            </xs:element>
 
             <xs:element name="owner_id" type="xs:integer"/>
             <xs:element name="date" type="xs:integer"/>
@@ -35,13 +52,13 @@
 
                     <xs:element name="max_thread">
                         <xs:complexType>
-                            <xs:attribute name="value"  type="xs:integer"/>
+                            <xs:attribute ref="value"/>
                         </xs:complexType>
                     </xs:element>
 
                     <xs:element name="max_cycles">
                         <xs:complexType>
-                            <xs:attribute name="value"  type="xs:integer"/>
+                            <xs:attribute ref="value"/>
                         </xs:complexType>
                     </xs:element>
 
@@ -55,19 +72,19 @@
 
                     <xs:element name="dimension">
                         <xs:complexType>
-                            <xs:attribute name="value"  type="xs:integer"/>
+                            <xs:attribute ref="value"/>
                         </xs:complexType>
                     </xs:element>
 
                     <xs:element name="size">
                         <xs:complexType>
-                            <xs:attribute name="value"  type="xs:integer"/>
+                            <xs:attribute ref="value"/>
                         </xs:complexType>
                     </xs:element>
 
                     <xs:element name="site_multiplicity">
                         <xs:complexType>
-                            <xs:attribute name="value"  type="xs:integer"/>
+                            <xs:attribute ref="value"/>
                         </xs:complexType>
                     </xs:element>
 
@@ -81,9 +98,9 @@
           </xs:element>
 
           </xs:sequence>
-          <xs:attribute name="id" type="xs:string"/>
-          <xs:attribute name="date" type="xs:integer"/>
-          <xs:attribute name="author" type="xs:string"/>
+          <xs:attribute ref="id"/>
+          <xs:attribute ref="date"/>
+          <xs:attribute ref="author"/>
           </xs:complexType>
       </xs:element>
 
@@ -93,18 +110,18 @@
 
               <xs:element name="arrow">
                   <xs:complexType>
-                      <xs:attribute name="x"  type="xs:integer"/>
-                      <xs:attribute name="y"  type="xs:integer"/>
-                      <xs:attribute name="z"  type="xs:integer"/>
-                      <xs:attribute name="site"  type="xs:integer"/>
-                      <xs:attribute name="weight"  type="xs:integer"/>
+                      <xs:attribute ref="x"/>
+                      <xs:attribute ref="y"/>
+                      <xs:attribute ref="z"/>
+                      <xs:attribute ref="site"/>
+                      <xs:attribute ref="weight"/>
                   </xs:complexType>
               </xs:element>
 
           </xs:sequence>
-          <xs:attribute name="id" type="xs:string"/>
-          <xs:attribute name="date" type="xs:integer"/>
-          <xs:attribute name="author" type="xs:string"/>
+          <xs:attribute ref="id"/>
+          <xs:attribute ref="date"/>
+          <xs:attribute ref="author"/>
           </xs:complexType>
       </xs:element>