Declaring Mixed Content

...
  <define name="personContent">
    <element name="NAME">
      <interleave>
        <text />
        <element name="GIVEN">
          <text/>
        </element>
        <element name="FAMILY">
          <text/>
        </element>
      </interleave>
    </element>
  </define>
...

personContent =
  element NAME {
    text
    & element GIVEN  { text }
    & element FAMILY { text }
  }