rail:formations 

container for complete train formations or sets of vehicles

http://wiki.railml.org/index.php?title=RS:formations

Element Information

Model

rail:formation+
Children: rail:formation

Source 

<xs:element name="formations" type="rail:eFormations" minOccurs="0">
  <xs:annotation>
    <xs:documentation>container for complete train formations or sets of vehicles</xs:documentation>
    <xs:documentation source="http://wiki.railml.org/index.php?title=RS:formations"/>
  </xs:annotation>
</xs:element>

Sample