-   The unique number assigned by the health provider to identify the eReferral.
-   This is also known as the provider's eReferral reference number.
-   It will be unique for each Referral on the provider level.

<xs:simpleType name="eReferralID">
    <xs:annotation>
        <xs:documentation>
        -   The unique number assigned by the health provider to identify the eReferral.
        -   This is also known as the provider's eReferral reference number.
        -   It will be unique for each Referral on the provider level.
      </xs:documentation>
    </xs:annotation>
    <xs:restriction base="xs:string">
        <xs:minLength value="1" />
        <xs:maxLength value="50" />
    </xs:restriction>
</xs:simpleType>