rail:speedProfileRef 

a reference to a speed profile; there could be several speed profiles to be considered

http://wiki.railml.org/index.php?title=TT:speedProfileRef

Element Information

Model

Attributes

QName Type Fixed Default Use Inheritable Annotation
ref rail:tGenericRef required 
reference is required because it's the purpose of the element
Wildcard: ANY attribute from ANY namespace OTHER than 'http://www.railml.org/schemas/2016'

Source 

<xs:element name="speedProfileRef" type="rail:tSpeedProfileRef" minOccurs="0" maxOccurs="unbounded">
  <xs:annotation>
    <xs:documentation>a reference to a speed profile; there could be several speed profiles to be considered</xs:documentation>
    <xs:documentation source="http://wiki.railml.org/index.php?title=TT:speedProfileRef"/>
  </xs:annotation>
</xs:element>

Sample