Exemple : Carnet d'adresse (XML, DTD, Relax NG)

<?xml version="1.0" encoding="UTF-8"?><?oxygen RNGSchema="adresse1.rnc" type="compact"?>

<addressBook>

  <card>

    <name>John Smith</name>

    <email>js@example.com</email>

  </card>

  <card>

    <name>Fred Bloggs</name>

    <email>fb@example.net</email>

  </card>

</addressBook>

<!ELEMENT addressBook (card*)>

<!ELEMENT card (name, email)>

<!ELEMENT name (#PCDATA)>

<!ELEMENT email (#PCDATA)>

<?xml version="1.0" encoding="UTF-8"?>

<element name="addressBook" xmlns="http://relaxng.org/ns/structure/1.0">

  <oneOrMore>

    <element name="card">

      <element name="name"><text/></element>

      <element name="email"><text/></element>

    </element>

  </oneOrMore>

</element>

element addressBook {

  element card {

    element name { text },

    element email { text }

  }+

}

<?xml version="1.0" encoding="UTF-8"?>

<grammar xmlns="http://relaxng.org/ns/structure/1.0">

  <start>

    <element name="addressBook">

      <zeroOrMore>

        <element name="card"><ref name="cardContent"/></element>

      </zeroOrMore>

    </element>

  </start>

  <define name="cardContent">

    <element name="name"><text/></element>

    <element name="email"><text/></element>

  </define>

</grammar>

namespace rng = "http://relaxng.org/ns/structure/1.0"

start = AddressBook

AddressBook = element addressBook { Card* }

Card = element card { Name, Email }

Name = element name { text }

Email = element email { text }

<?xml version="1.0" encoding="UTF-8"?>

<grammar

  xmlns="http://relaxng.org/ns/structure/1.0"

  datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">

  <start>

    <element name="addressBook">

      <zeroOrMore>

        <element name="card"><ref name="cardContent"/></element>

      </zeroOrMore>

    </element>

  </start>

  <define name="cardContent">

    <element name="name"><data type="string"/></element>

    <element name="email"><data type="anyURI"/></element>

  </define>

</grammar>