<?xml version="1.0" encoding="UTF-8"?>
<grammar xmlns="http://relaxng.org/ns/structure/1.0" 
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
  <start>
      <ref name="element-alerts"/>
  </start>

  <define name="element-alerts">
    <optional>
    <element name="alerts">
      <zeroOrMore>
        <element name="alert">
          <attribute name="id"><data type="ID"/></attribute>
          <optional>
            <attribute name="description"><text/></attribute>
          </optional>
          <!-- path to the script called for alert -->
          <attribute name="path"><text/></attribute>
          <ref name="element-alert-extra"/>
          <zeroOrMore>
            <element name="recipient">
              <attribute name="id"><data type="ID"/></attribute>
              <optional>
                <attribute name="description"><text/></attribute>
              </optional>
              <attribute name="value"><text/></attribute>
              <ref name="element-alert-extra"/>
            </element>
          </zeroOrMore>
        </element>
      </zeroOrMore>
    </element>
    </optional>
  </define>

  <define name="element-alert-extra">
      <zeroOrMore>
        <choice>
          <element name="meta_attributes">
            <externalRef href="nvset-1.3.rng"/>
          </element>
          <element name="instance_attributes">
            <externalRef href="nvset-1.3.rng"/>
          </element>
        </choice>
      </zeroOrMore>
  </define>

</grammar>