Here's an XML schema that matches the original name and address DTD. It adds two constraints: The value of the <state> element must be exactly two characters long and the value of the <postal-code> element must match the regular expression [0-9]{5}(-[0-9]{4})?. Although the schema is much longer than the DTD, it expresses more clearly what a valid document looks like. Here's the schema:

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:element name="address">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="name"/>
        <xsd:element ref="street"/>
        <xsd:element ref="city"/>
        <xsd:element ref="state"/>
        <xsd:element ref="postal-code"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>

  <xsd:element name="name">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element ref="title" minOccurs="0"/>
        <xsd:element ref="first-Name"/>
        <xsd:element ref="last-Name"/>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>

  <xsd:element name="title"      type="xsd:string"/>
  <xsd:element name="first-Name" type="xsd:string"/>
  <xsd:element name="last-Name"  type="xsd:string"/>
  <xsd:element name="street"     type="xsd:string"/>
  <xsd:element name="city"       type="xsd:string"/>

  <xsd:element name="state">
    <xsd:simpleType>
      <xsd:restriction base="xsd:string">
        <xsd:length value="2"/>
      </xsd:restriction>
    </xsd:simpleType>
  </xsd:element>

  <xsd:element name="postal-code">
    <xsd:simpleType>
      <xsd:restriction base="xsd:string">
        <xsd:pattern value="[0-9]{5}(-[0-9]{4})?"/>
      </xsd:restriction>
    </xsd:simpleType>
  </xsd:element>
</xsd:schema>