<?xml version=“1.0”?> <schema xmlns=“www.w3.org/2001/XMLSchema

      xmlns:foo="http://FOO"
      targetNamespace="http://FOO" version="0.1"
      elementFormDefault="qualified">

<complexType name="fooType">
  <choice>
    <sequence>
      <element name="PGPKeyID" type="base64Binary"/>
      <element name="PGPKeyPacket" type="base64Binary" minOccurs="0"/>
      <any namespace="##other" processContents="lax" minOccurs="0"

maxOccurs=“unbounded”/>

</sequence>
<sequence>
  <element name="PGPKeyPacket" type="base64Binary"/>
  <any namespace="##other" processContents="lax" minOccurs="0"

maxOccurs=“unbounded”/>

    </sequence>
  </choice>
</complexType>

<element name="foo" type="foo:fooType"/>

</schema>