Skip to main content
  • Subscribe by RSS
  • Ex Libris Knowledge Center

    Formatting and interpreting System-ID in ISO ILL

    • Article Type: General
    • Product: Aleph
    • Product Version: 18.01

    Institution Symbols are used in ISO ILL to uniquely identify both the sender and the recipient of all messages between borrower and lender. These symbols, referred to in the protocol as Requester-Id and Responder-Id, must be universally unique. To insure this, a naming scheme has been devised by the ISO ILL Maintenance Agency (currently the national Library and Archives of Canada). The Maintenance Agency registers authorized ‘Name Authorities’. These Name Authorities are organizations or institutions that may assign codes or symbols representing users of the ISO ILL protocol. These Name Authorities are assigned a ‘Namespace’. The namespace for OCLC is ‘oclc’. Ex Libris has also been registered as a Name Authority. The Ex Libris Namespace is ‘exl’. This link lists all of the Name Authorities registered with the Maintenance Agency:
    (Note that the Library of Congress is not a registered Name Authority, and that NUC symbol, therefore, cannot be used for the purpose of specifying Institution Symbol.)

    A Name Authority has the responsibility of ensuring that every symbol defined within its Namespace is unique to that Namespace. OCLC insures that every OCLC symbol is unique within the OCLC Namesake. Ex Libris, because it has asked the Maintenance Agency for the right to represent a Namespace, needs to devise a method for our customers to define a unique symbol within the ‘exl’ namespace. It is also assumed that Name Authorities will provide a mechanism for symbols within its Namespace to be validated and resolved. This will permit a lending institution that receives an ISO ILL Request from a library identified with an Institution Symbol in the ‘exl’ namespace to identify that library.

    The format for the Institution Symbols used for Requester-Id and Responder-Id is:
    <Namespace>:<Symbol within Namespace>

    An example of an Institution Symbol in the OCLC Namespace would look like:
    This represents Minnesota State University, Mankato

    A possible format for the same institution within the exl Namespace might be:
    Ex Libris should codify a method for creating unique symbols within its Namespace.

    Additional considerations regarding the formatting and interpretation of System-Id are discussed in the ILL Protocol Implementors Group (IPIG) Profile:
    and the IPIG Guidelines document:
    including field length limitations (25 characters) and how to interpret System-Id strings with more than one colon (Consider the first colon as a separator and subsequent colons as part of the notation for the Symbol. Note that National Library of Australia is a Name Authority – nla – and the symbols it assigns typically include an embedded colon.)

    One final thing about System-Id’s. ISO ILL Messages compliant with the IPIG Profile can contain more than one System-Id representing the libraries associated with an ILL Request. This is done through use of Aliases.

    • Article last edited: 10/8/2013