dotml:node-port

<xs:simpleType name="node-port">
  <xs:annotation>
    <xs:documentation>Port where an edge can atach to a node.</xs:documentation>
  </xs:annotation>
  <xs:restriction base="xs:string">
    <xs:enumeration value=":n"/>
    <xs:enumeration value=":ne"/>
    <xs:enumeration value=":e"/>
    <xs:enumeration value=":se"/>
    <xs:enumeration value=":s"/>
    <xs:enumeration value=":sw"/>
    <xs:enumeration value=":w"/>
    <xs:enumeration value=":nw"/>
  </xs:restriction>
</xs:simpleType>