ConditionGroup 

To express more complex rules

Element Group Information

Model

Condition | Conditions
Children: Condition, Conditions

Used By

Element Conditions
Complex Types RuleQuantityType, RuleType

Source 

<xs:group name="ConditionGroup">
  <xs:annotation>
    <xs:documentation>To express more complex rules</xs:documentation>
  </xs:annotation>
  <xs:choice>
    <xs:annotation>
      <xs:documentation>List of single or combined conditions</xs:documentation>
    </xs:annotation>
    <xs:element ref="Condition"/>
    <xs:element ref="Conditions"/>
  </xs:choice>
</xs:group>