<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">

<xs:element name="icmptype">
  <xs:complexType>
    <xs:choice maxOccurs="unbounded">
      <xs:element name="short" type="xs:string" minOccurs="0"/>
      <xs:element name="description" type="xs:string" minOccurs="0"/>
      <xs:element name="destination" type="desttype" minOccurs="0" maxOccurs="unbounded"/>
    </xs:choice>
    <xs:attribute name="version" type="xs:string"/>
  </xs:complexType>
</xs:element>

<xs:complexType name="desttype">
  <xs:attribute name="ipv4" type="booltype"/>
  <xs:attribute name="ipv6" type="booltype"/>
</xs:complexType>

<xs:simpleType name="booltype">
  <xs:restriction base="xs:string">
    <xs:pattern value="[Yy]es|[Nn]o|[Tt]rue|[Ff]alse"/>
  </xs:restriction>
</xs:simpleType>

</xs:schema>