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ISO ILL

ISO ILL: The international standard for interlibrary loan

ISO ILL 10160/10161 is the technical definition of messages as well as a set of rules on how to use those messages between systems. Many libraries who use multiple ILL methods are implementing ISO ILL compliant systems because they enable the libraries to manage all of their ILL transactions in a single database. Depending on the system, this allows them to take advantage of other system features such as copyright tracking or searching bibliographic databases.

ISO ILL messaging is modeled on pre-OCLC paper-based workflows. The “requestor” sends a request to the “responder”. The responder either replies that the material is on its way or says “no”. Because the workflow is familiar, most of the messages (called APDUs) are also familiar, such as “renewal request” or “conditional”. However, since this is automated messaging between systems there are other APDUs) that are new to OCLC ILL such as “status or error report”.

Peer-to-peer transactions instead of a central system

The primary difference between OCLC ILL's central system method and the “peer-to-peer” method used by other ISO ILL systems is that OCLC ILL users share a single copy of the request. On OCLC, when the borrower is working with the request, the lender is prevented from accessing it. When the status of a request is changed, it is changed for both the borrower and the lender immediately.

In contrast, the ISO ILL borrower and lender each have their own copy of the request, just like with the old paper forms. Because there are two copies of the request, it is not possible to ensure that only one partner is working on a request at any given time. There also may be a time delay between when messages are sent and received. To prevent requests from becoming out of agreement, for example, conditional on the lender side and canceled on the borrower's, the protocol has additional messages to keep requests in agreement. There are other, optional, messages like that allow systems to try to bring requests back into agreement should they become out of agreement.

ISO ILL interactions and OCLC

OCLC's ILL system supports the full range of required messages. Libraries can choose to interact with OCLC ILL using the ISO ILL protocol as borrowers, as lenders or as both. To begin using an ISO ILL system with OCLC ILL you need to purchase or build an ISO ILL compliant system that is able to interact with OCLC ILL.