P5: Directrices para la codificación y el intercambio de textos electrónicos

<rng:element name="milestone">
<rng:ref name="att.global.attributes"/>
<rng:ref name="att.typed.attributes"/>
<rng:ref name="att.sourced.attributes"/>
<rng:attribute name="unit">
 <rng:choice>
  <rng:value>page</rng:value>
  <rng:value>column</rng:value>
  <rng:value>line</rng:value>
  <rng:value>book</rng:value>
  <rng:value>poem</rng:value>
  <rng:value>canto</rng:value>
  <rng:value>speaker</rng:value>
  <rng:value>stanza</rng:value>
  <rng:value>act</rng:value>
  <rng:value>scene</rng:value>
  <rng:value>section</rng:value>
  <rng:value>absent</rng:value>
  <rng:value>unnumbered</rng:value>
  <rng:data type="Name"/>
 </rng:choice>
</rng:attribute>
<rng:empty/>
</rng:element>

element milestone
{
   att.global.attributes,
   att.typed.attributes,
   att.sourced.attributes,
   attribute unit
   {
      "page"
    | "column"
    | "line"
    | "book"
    | "poem"
    | "canto"
    | "speaker"
    | "stanza"
    | "act"
    | "scene"
    | "section"
    | "absent"
    | "unnumbered"
    | xsd:Name
   },
   empty
}