ISO ILL Protocol
Contribution to eLib Study on Document Requesting Standards

Version 1.1
18 November 1997
Ruth Moulton, Fretwell-Downing 
ruth@muswell.demon.co.uk

Contents
Contents	
2. Overview of the standards for handling requesting	
2.(ii) ILL Protocol	
4. The ILL Protocol	
4.1 Description	
4.1.1  Models of Interaction	
4.1.2 ILL Services Provided by the Protocol	
4.1.3 Extensibility and Flexibility	
4.1.4 Message Formats and Transport Mechanisms	
4.1.5 ILL Protocol Machine States	
4.1.6 Conformance	
4.2 Development of the Standard and Profiles	
4.2.1 Development of the Standard	
4.2.2 Profiles	
4.2.3 Related Standards Activities	
4.3 Implementors Fora	
4.4 Service Environment	
4.5 Implementations	
4.6 References and URLs	

2. Overview of the standards for handling requesting
2.(ii) ILL Protocol

The ISO InterLibrary Loan Protocol (ISO ILL) [ILL] was developed to provide uniform procedures when accessing a library across a network to order copy or loan material, and for carrying out the administrative tasks involved in loan management. However it only provides ordering and loan management functionality, it does not provide any services to search for or locate an item nor to have the item delivered electronically and although it provides some facilities for billing and accounting, these are fairly simple.

The standard defines a number of services available to the requesting site and the supplying site. The standard models the activities involved in a variety of scenarios, which include

•	Simple request (with a reply indicating failure to  supply),
•	Request for the loan of an item with full tracking of  the loan including recall notices, renewal request,   reporting of lost or damaged items,
•	An unsatisfied request being passed to a backup library  for supply.

Services are carried out by the exchange of messages between the requesting site and the supplying library. The standard defines the content and format of the messages, together with encodings that allow them to be transmitted over the network. The messages may be transmitted as e-mail messages or directly over a network connection made between the requester and supplying library. Although the protocol was originally designed as an application in the ISO OSI  model, in other words to be used within an X.25 network using connection services or X.400 e-mail, it has in fact only been used in an Internet environment, using RFC822 e-mail services or a direct connection over TCP/IP protocols. Current e-mail developments of the protocol are using the MIME extensions of RFC822 mail.

The ILL messages are not designed for direct human consumption but rather for exchange between ISO ILL software that will interpret the messages, keep track of the state of the ILL transaction and send replies as and when necessary. The ILL software would probably be part of a larger ILDRMS system which would have its own user interfaces (Figure 1). Before messages are transmitted over the network they are first encoded to allow the information to be transmitted in an unambiguous and efficient manner rendering the messages unreadable for humans. In most cases the Basic Encoding Rules (BER.1) are used for this, however the standard does define an EDIFACT encoding, allowing the messages to be transmitted using pure ASCII characters for transmission over RFC822 e-mail. The ILL EDIFACT messages are not registered in an EDIFACT Directory and bear no relationship to the EDI messages discussed elsewhere in this report.

Printed Books and Journals

Requester’s Library System

Supplying Library’s Loan Management System

ISO ILL Protocol Messages

User Interface

Scaning or Librarian Workstation

ISO ILL Protocol Module

ISO ILL Protocol Module

Online Catalogue and electronic documents

Independent Physical or Electronic Delivery of Item, 

Invoicing and Payment

Figure 1

When a request is sent to a library this starts a new transaction. The transaction continues until the item is satisfactorily supplied and, if a loan item, satisfactorily returned, or the supplying library notifies that it cannot supply the item. Transactions may last for a few seconds or minutes, if the supplying library has electronic access to its catalogues and is supplying documents held electronically over the network, or may last for months, for example where a loaned item is renewed.  

4. The ILL Protocol

4.1 Description

The ISO InterLibrary Loan Protocol (ISO ILL) was developed to provide uniform procedures when accessing a library across a network to order copy or loan material, and for carrying out the administrative tasks involved in loan management. The protocol is described and defined in two standards documents: ISO 10160 Interlibrary Loan Application Service Definition and ISO 10161 Interlibrary Loan Application Protocol Specification [ILL]. The standard was first approved by ISO in 1991 after several years of collaborative international development, consultation and review.

The standard defines a number of messages that can be sent between the requesting site and the supplying site in order for the requester to access the different services that might be offered by the supplying organisation. It is likely that a supplying organisation will be a library, but a requester might be a library managing requests on behalf of a patron, or might be a patron ordering directly  [ZEE]  Most of  the services are unconfirmed in that there is no indication from the recipient of a message that it has been received other than obvious action following on, e.g. after a request for a document has been sent a message might be received saying that the document is on it’s way to the requester (i.e. has been shipped), or the document itself might arrive. 

An ILL transaction starts when an ILL-Request message is sent (and received). The ILL-Request message includes a unique identifier for the transaction it is initiating. All following messages associated with this transaction will carry the identifying transaction identifier. A transaction may end at different points depending on the nature of the transaction, e.g. a loan might continue until the Returned service is complete, a transaction requesting a copy of an item might continue until the Shipped services is complete.

In general a transaction goes through several stages: request; failure or notification of shipping of the item; acknowledgement of receipt of the item; reminders to return loaned items; return of item or notification of lost item; acknowledgement of receipt of returned item. The standard formally divides these stages into two phases, namely the processing phase which lasts from request until either shipped notification or notification of failure to supply, followed, for loan items only, by the tracking phase.
 
The protocol is implemented in a software module termed a protocol machine which would interact with other parts of a loan management system or user interfaces (see section 2.ii Figure 1). The standard specifies the different states a protocol machine might be in and the actions that might be legally taken from each state.

4.1.1  Models of Interaction

The standard defines 3 roles that a system might perform:

•	Requester - the system will request a copy or loan of an item, will accept the item and will manage the return of a loaned item. It may also make reports if an item is lost or in a damaged state.
•	Responder - the system will receive a request, either satisfying it or replying that it cannot do so. Supply of the item, and it’s return if a loan, is managed.
•	Intermediary - A system  initially contacted as a Responder which is unable to satisfy a request  and forwards the request onto another responder. An intermediary may stay in the loop passing messages between Requester and Responder or may drop out leaving the two parties to communicate directly with each other.

A given system may be capable of taking any or all of the roles but in any given transaction it may behave only as Requester, Responder, or as Responder turned Intermediary, on the other hand it may only be capable of taking on one role but still remains a system conforming to the Standard.

A number of models of interaction between Requester, Responder and Intermediary are suggested in the standard:

•	Simple Transaction - here the requester and responder communicate directly with each other, if the request cannot be satisfied the transaction finishes (Fig. 1).

 	

 	
 	
 	Chained Transactions - In this model if a responder cannot satisfy a request it changes role to that of an intermediary and passes, or forwards, the request onto another potential responder. This is repeated until there are no more responders to try or a responder can supply the requested item. Each intermediary stays in the communications chain passing messages between the requester and the responder. The intermediary role might continue for delivery of the item or the item might be delivered directly to the requester, this issue is outside the standard (Fig. 2).

 	In a variant of the chained model if an intermediary passes the request to a responder that cannot satisfy the request then the intermediary may pass the request to another responder. This gives rise to a star topology where at most one of the branches  may complete a transaction by supplying the item other branches complete with the request unfilled (Fig. 3).

•	Partitioned Transactions - This model resembles the chained model except that once the processing phase is complete, i.e. after an item has been sent off to the requester (shipped) then all further ILL messages that pass between the requester and supplier do so directly, not via the intermediary (Fig 4).

The requester has some control over the actions of the responder in the case of unfilled requests, it may allow or  forbid the responder from passing on the request, i.e. becoming an intermediary and may also supply a list of alternate libraries that have already been tried or might be tried by an intermediary. If a responder cannot satisfy a request it too may supply a list of alternate suppliers that an intermediary or the requester may try. 

Where an intermediary is involved the transaction takes place between the requester and the first intermediary, and subtransactions take place between the intermediary and any other intermediaries or responders. It is allowable to mix partitioning and chaining where an intermediary is involved (Fig 5).

4.1.2 ILL Services Provided by the Protocol

The standard defines a number of services that are made available by the protocol, each service is performed by the exchange of one or more messages between requester, responder or intermediary systems.

Services for Requesting an Item

•	Request Service - ask for an item

 	A requester sends an ILL-Request message to a potential supplier to ask for a copy of an item, a loan of an item, information about the location of the item, or an estimate of the cost of the service being requested. The message contains a number of pieces of information:
 	
"	identification of the item, this may be a bibliographic description of the item or simply a shelf mark or system number. It may also include extra machine readable information such as a MARC record.

"	where to send the item to, and what method to use. This may be used for a request for electronic delivery of the item (i.e. e-mail, fax etc.) or physical delivery (post, special delivery etc.).

"	information identifying the organisation or person making the request as well as the supplier of the material.

"	a unique transaction identifier which will be used for the whole of the transaction.

"	required service, i.e. loan, copy, estimate and locations.

"	further constraints, e.g. date by which item is needed, format of delivered item (e.g. microform), request item be put on hold if not immediately available.

"	accounting information such as account number or payment agreements and maximum amount the requester is willing to pay.

"	where to send invoices, this may be a physical or electronic address.

"	copyright regulations or laws to which the requester is adhering.
 	
•	Request Forwarding - used to forward a request 

The library receiving a request cannot supply the item, or is only acting as an intermediary, so uses this service to forward the request onto  another library.

•	Forwarding Notification - notify requester that a request has been forwarded to another library

The library which sent the request to another library uses this message to inform the requester that this has happened and includes details identifying the new library.

•	Renewal - used to renew the loan of an item

The requester who has borrowed an item may use this service to renew the loan. The message contains the transaction identifier which must be used to determine the item that is on loan, as well as the borrowers identification. It also carries the date until which the borrow wishes to renew the loan. 

Responses to a Request   

•	Answer - reply in response to a request for an item

This service enables a supplying library to respond to a request for an item, there are five kinds of answer that may be given:

"	The library cannot supply the item, so the request is rejected.

"	The library cannot immediately supply the item but might be able to do so if the requester were to try again at a later date, this finishes the current transaction.

"	The library may be able to supply the item, but needs certain conditions to be satisfied, e.g. the requester must agree to an increased charge for the supply of the item, or to abide by a copyright agreement, the Conditional Reply service (below) is used by the requester to indicate agreement (or not) to the condition.

"	The library is supplying information such as an estimated cost for the supply, or locations information about the item.

"	The item will be supplied at some time in the future, either the item is not available at present but will be supplied when it becomes available (a hold has been placed) or there is going to be some delay before the item is supplied.

 	In all cases the message includes further details explaining the response that has been given or further information for the requester, such as a date after which to retry the request.

•	Conditional Reply - requester may accept or reject a condition placed on the supply of an item
 	
Where an Answer to a Request indicated further conditions must be met, the Conditional Reply service is used to indicate whether or not the requester is prepared to accept the conditions set by the supplier. The message allows a simple yes/no answer, so if the condition is rejected (answer is ‘no’) this terminates the transaction.

•	Renew Answer - the supplier of a loaned item may accept or reject request for renewal

This service is used to accept or reject the request to renew the loan. The message will contain the new date the item must be returned by, if the loan is being renewed, this may be set by the library or accepted from the Renew Request message (see below).

Request Management

•	Shipment - indication that the requested material has been supplied

The purpose of this service is that the supplying organisation can inform the requester that the item is ‘in the post’, i.e. has been sent. For electronic delivery it may well be that this message reaches the requester after the item itself ! This service does not necessarily indicate, however, that the item has arrived. The service also serves as an indication that the item is being supplied, i.e. a positive response to a request. The message contains details about :

"	the supply, such as date of supply, total cost of the service, 

"	insurance of the item, 

"	details about the shipping, such as via whom the item was shipped. 

"	For a loaned item this message contains the address to which the item is to be returned.

•	Cancellation - allows the requester to cancel the request

This allows the requester to ask that a request, identified by the transaction identifier carried in the message, be cancelled. There is no guarantee of success: the item may already have been supplied, the supplying library may not allow cancellations etc. The Cancellation Reply, below, is used for the supplier to indicate the result of this request.

•	Cancellation Reply - allows the supplier to indicate the result of a request for cancellation

The supplying organisation may say whether or not it is prepared to cancel the request made by the requester, the message carries a simple yes/no reply.

•	Receipt - the requester may use this service to indicate that the item was received satisfactorily.

•	Damaged Notification - this service to indicate that the item has been  damaged

The Damaged message may be sent by either the requester to indicated a supplied item is damaged or by the supplier to indicate that a returned item has arrived in a damaged state. The service may apply to electronic items as well as physical ones, in this case ‘damaged’ means that the item cannot be read correctly. It may also be used if a loaned item is damaged whilst in the possession of the requester. The message includes  a description of the damage. 

•	Message - a message may be sent 

This service simply allows a free form text message to be sent to either the requester or the supplier, intended to be read by a person, so it might be used to send a message directly to a librarian, as an example.

•	Status Query - used to find the status of a transaction

This service may be used by either the requester or the supplier to discover the status of the transaction, indicated in the message by the transaction identifier, as understood by the other party. As an example the requester could make this request if it hadn’t received an answer to a request and was worried that an answer message had been lost, or the supplier could make this request to determine if an item had been received in the absence a Received message. Some services, such as Received, need only be optionally supported, so the Status Query/ Status-or-Error Report can sometimes be used to make up for the lack of support of a service.

•	Status-or-Error Report - sends the current status of the transaction or an error report

The service is used to inform the other party of the state of the transaction at the site sending the message. It might be used in response to a Status Query or be sent unilaterally. It is also used where the recipient of a message detects an error, for example if it does not support the required service.

•	Expiry - a transaction has terminated

This service is used to inform the other party that a given transaction has been terminated due to a time out period elapsing. A transaction may have timed out because a response was not received within the requested period (e.g. Answer or Shipped not received within the expiration date set in a Request message). Because the ISO ILL services are unconfirmed it is possible for a message to get lost in transit and the sender and recipient not know about this, thus a transaction terminating message may be lost and the transaction left to time out. It is also possible that in some library systems it is not possible to detect when a transaction has terminated, as an example at the British Library when unfilled requests are passed to a backup library the information about the remainder of the transaction does not pass back through the automated request system (ART), so if the request were being carried out with ISO ILL interface the ISO ILL transaction might not receive information terminating the transaction. 

Loan Management

•	Overdue - the supplying library may notify the borrower that a loan is overdue

This service is used by the supplying library when a loaned item is due to be returned. It would expect the borrowing system to either return the item or to issue a request to renew the loan period.

•	Recall - the supplying library may request the immediate return of  loaned item.

This service expresses a more severe notification from the supplier. Here the supplier would expect the item to be returned immediately with no further possibility of renewal.

•	Return - the requester notifies the supplier that a loaned item has been returned

Here the requester who has borrowed an item is notifying the supplier that the item has been returned, it is similar to the Shipped service in that it indicates the item has been sent, but not necessarily been received. From the requesters point of view it means that the transaction has reached termination.

•	Checked-In -  a loaned item has been received back by the supplier

This service is similar to the Received service in that it notifies the requester that a loaned item has been received by the supplier. This service indicates that the transaction has terminated. Thus it can also be used by the supplier to force ending of the transaction at both ends, even if this state has been reached by some means other than a returned item.

•	Lost Notification - notification that an item has been lost

 	This service may be used by the person or organisation that had loan of an item to indicate to the supplier that the item has been lost. It may also be used by the supplier to notify to the requester that the item has been lost (e.g. although in the holdings catalogue it cannot be found). In either case the ILL transaction ends at both organisations.

In addition to information about the service carried in each message, some of which has been identified above, each message contains a Notes field that may contain further free text information about the service.
4.1.3 Extensibility and Flexibility

The protocol is also extensible, each message contains an Extension field which may carry more information in a structured format whose format and usage may be defined outside of the standard. The extensions may be defined solely between the systems using the protocol, for example clients using the OCLC system would use the extensions specified by OCLC, but there are also publicly defined extensions being developed which allow the protocol to be extended without having to go through the lengthy activities involved in getting changes to the standard approved. These extensions will probably be formally incorporated into the standard, unless their use proved them to be of no value. These extensions are often used to fill the gap between the standard and an existing library system, as an example the British Library allows a richer set of bibliographic description than is present in the standard and could use an extension to carry this information, OCLC uses proprietary  extensions to indicate further error conditions and request information when accessing the Prism system. One important extension that is being agreed for the request service is one which allows more sophisticated authentication than is currently catered for by the standard. 

The protocol is very flexible and allows a requesting or supplying library to use the particular set of messages which models is own services and procedures, since it is optional for a system to support some of the messages and fields within the messages. As an example a system that supported only the responder role need only support the supply of either loans or copies and need only support Shipped, Answer, Cancel Reply, Lost and Status-or-Error Report services if offering only the supply of copies, on the other hand it could offer both kinds of supply and support all the services described above. The particular set of services and facilities within those services that a particular system supports is called a profile.

This same flexibility means there is a risk that a system using ISO ILL to request items will not interwork with a supplier’s ISO ILL system if the same profile has not been followed, there are several organisations involved in defining profiles that will be published in the public domain to avoid problems of non interworking, they are described more fully below.

4.1.4 Message Formats and Transport Mechanisms

The standard specifies the format of the messages (their syntax), the items of information that may be carried in a particular message and the way in which particular messages, items or values of items should be interpreted (their semantics). The message formats are defined in the language called Abstract Syntax Notation 1 (ASN.1) , developed specifically by ISO for description of communications messages. In ISO standards, messages are referred to as Application Protocol Data Units or APUDs.

The standard also specifies that the messages may be carried over the network in one of two ways:

•	over direct connections made across the network, i.e. by using an X.25 connection or an Internet TCP/IP connection. Although the protocol was originally designed to be used over X.25 connections the Internet protocols (TCP/IP) have become much more widely deployed and so in practice only TCP/IP connections have been used with the ISO ILL protocol. Connection oriented protocols are most suited to interactions that have a relatively short lifetime (minutes or hours) where rapid and reliable responses are needed.

•	within e-mail messages. This is also known as ‘store-and-forward’ due to the way e-mail messages are transmitted through a network, or between networks.

 	This has proved to be the most common approach to date, probably because of the potentially long life time of a transaction (up to months or years for a loan). When the standard was first published and the protocol implemented the most common e-mail standard in use was Internet RFC-822, originally designed to carry plain text interpersonal messages between people. It’s draw back is that the message formats are relatively simple and may only be composed of US ASCII text. This standard has now been extended with the MIME standards so that structured messages containing ‘binary’ information may be transmitted. X.400 messages could also be used, but again, because of the popularity of the Internet, X.400 messaging has been used very little. 
 	
 	E-mail is useful when an interaction consists of messages being sent sporadically over long periods of time (days, weeks or months), but because of the store-and-forward technology used to transmit e-mail messages rapid responses cannot be guaranteed. Nowadays e-mail systems are fairly reliable and it is not often that messages are lost, Internet e-mail systems are now capable of sending receipt notifications so that a more reliable service may be set up.

The standard does not give sufficient detail about how the transport mechanisms should be used, but work is now being done to address this issue, necessary if good interworking  between ISO ILL systems is to be achieved. It would also be possible to use both transport mechanisms: for example the processing phase could be carried out over TCP/IP connections, where the requester would like a rapid answer about the possibility of being able to obtain the required material, but the tracking phase could be carried out using e-mail where the interactions are in any case taking weeks or months.

Before a message is transmitted over the network it must be encoded in some way. The encoding ensures that the structure of the message is maintained (as described in ASN.1) and that numeric, text and other non text values are transmitted in a way understood by both sender and receiver of the message. The standard specifies two encoding methods for transmitting the ILL messages:

•	Basic Encoding Rules (BER) is ‘binary’ or ‘8 bit’ encoding that is intended for use over connection oriented services such as TCP/IP or X.25 and e-mail services that can transmit 8 bit data such as X.400 and MIME. All these services allow transmission of binary data, where all 8 bits in a transmitted byte may be used to denote the data being transferred.

•	EDIFACT text encoding which is intended solely for use with RFC822 e-mail transport services. The standard specifies formats for messages using the 1988 version of ISO 9735 EDIFACT  syntax rules. These messages have not been registered in the EDI directory and do not represent a use of EDI as such, rather it is a mechanism to generate ISO ILL messages in ‘7 bit’ ASCII text data, where only the 7 least significant bits of every transmitted byte are used to carry data.

It can be seen that there is a grave risk of non-interworking with these encodings and transport mechanisms, for example a system written to receive messages encoded in BER.1 would not understand messages encoded in EDIFACT, a system receiving requests over TCP/IP would not be reading e-mail to look for the messages and so on. So far development of the protocol has not been wide spread, or has been within projects only needing interworking amongst project participants, but the problem has become more urgent now that there is  growing interest to develop operational systems using the standard.

The Library Corporation (TLC, Western Virginia, USA)  has recently developed a gateway (TLC call it a transponder) that will help to ease this problem, and is currently being tested . It will allow interworking between systems using different encoding methods and different communications methods. The TLC has developed an extension to be used in each message which will contain extra network addressing and protocol information. 
 4.1.5 ILL Protocol Machine States
The standard includes complete state tables for each protocol role which specifies the various states that an ILL transaction  ILL protocol machine may legally be in for a given transaction, and what actions are legal for each state, i.e. what action to take on receipt of specific messages and which messages may be sent. It is these states that are identified in the Status-Or-Error Report message. Some examples, from 26 pages or tables,  are:
•	a Requester in the idle state may accept an ILL-Request message, taking it into the pending state, the arrival of any other message is considered an error
•	a Requester in the cancel-pending state after having sent a Cancel message, if a Cancel Reply is received the requester goes into the cancelled or pending state depending on the response (acceptance or rejection).
•	a Responder is in the shipped state having sent the Shipped message, it is also then in the tracking phase. If the ILL application indicates that the item has been returned a Checked In message may optionally be sent and the responder goes into the checked-In state.
4.1.6 Conformance
An implementation does not need to implement the complete protocol. The standard specifies the minimum requirements that an implementation must reach before it may be considered to conform to the protocol:
•	implement only one of the three roles (requester, intermediary or responder).
•	support simple transactions if acting as responder or requester, support one of chained or partitioned if acting as intermediary.
•	support either loan or copy services.
•	as requester support ILL-Request, Conditional-Reply, Received, Lost and Status-or-Error-Report services and, if supporting Loans must also support the Returned service.
•	as responder support Shipped, ILL-Answer, Cancel-Reply, Lost and Status-Or-Error-Report services. If supporting Loans then must also support Recall, Checked-In, Overdue and Renew-Answer services.
•	as intermediary support Ill-Request, Conditional-Reply, Status-Query, Status-or-Error Report, Shipped, Received, Ill-Answer, Cancel, Cancel-Reply, Lost, Damaged and if supporting Loans must also support Recall, Overdue, Checked-In, Renew, Renew-Answer and Returned.
•	must be able to receive all messages and all data elements, although need not do anything with them if the appropriate services are not supported.
•	must be able to support all the mandatory options for message fields in the supported services
•	must be able to define the data in the optional message fields in the supported services

4.2 Development of the Standard and Profiles
4.2.1 Development of the Standard

Development of the protocol began in the early 19080s and after a number of years of international co-operation the protocol was adopted by the International Standards Organisation Technical Committee 46,  Subcommittee 4, Working Group 4 (ISO/TC46/SC4/WG4), the committee which looks after Library Automation Applications. The effort was spearheaded by the library community in Canada (NLC) and Scandinavia, but gained international participation from other groups (notably the British Library and German Library community) and from the two fora EWOS/EG-LIB and IFOBS, mentioned below. NLC host the IFLA ILL Protocol Resource WWW page [ILLRESOURCE]which contains details about obtaining the standards, tabled amendments, profiles, papers and other resources.

The first edition of the protocol was published by ISO in 1993 with a second edition published in 1996. Apart from corrections the main addition was to enable request for electronic delivery of items. The standard has been stable for some years, but with a reasonably large number of projects and developments currently underway, it is likely that new operational experience is likely to lead to a number of changes to the protocol.

The North American Interlibrary Loan and Document Delivery Project (NAILDD), run by the Association of Research Libraries (ARL),  has set up an implementors group, now open to international membership, called  IPIG (ILL Protocol Implementors Group), described further in section 4.3 [IPIG]. The group is likely to submit proposals for changes to the protocol.
4.2.2 Profiles
The Standard specifies various options available within the protocol, as an example most elements of Item identification are optional (although at least one of them must be present) in a request message and not all the services must be supported. The issue of how to transmit the messages (APDUs) is also not defined explicitly by the standard, as discussed above. These optional facilities whilst making the protocol more versatile give rise to interoperability problems between different implementations. To lessen the impact of such problems implementors may agree to specific choices for some of the options, and these agreements are expressed as profiles of the protocol.

An International Standardized Profile (ISP) was written by EWOS EG/LIB  and IFOBS (see section 4.3) and published by ISO in 1996. The profile is several parts: a basic profile covering the protocol itself, a profile for using the protocol with ACSE (Association Control Service Element, a profile for using X.25 connections), a profile for using the protocol with store and forward transport mechanism (X.400). This ISP has formed the starting point for the IPIG profile currently under development.

The DALI (Document and Library Integration) project, which was funded by the European Commission, included an implementation of the ILL protocol, using it over TCP/IP. As part of this project a draft RFC profiling the use of TCP/IP for transmitting ISO ILL messages has been issued for approval within the ISO ILL community, it has been circulated to members of the IPIG and EFILA [ILLTCP].

As mentioned above, the IPIG are developing a profile for use of the protocol amongst it’s members. This will be a profile for the protocol, and the group is also considering profiles for the use of MIME [MIME] e-mail and TCP/IP.
4.2.3 Related Standards Activities

Group on Electronic Document Interchange

In a number of projects such as EDIL[EDIL], JEDDS [JEDDS] and UNIverse [UNI](described briefly below in section 4.5), the ISO ILL protocol is used to request items that are transmitted using the GEDI [GEDI]agreement. This entails adding a cover to the document containing meta-data about the document including format and bibliographic information, its recipient and supplier, the means by which it should be transmitted and a transaction identifier referring to the transaction by which it was requested (e.g. ISO ILL Transaction-Id).

Where ISO ILL has been used to order the document much of the cover information can be  derived from the ILL Request message, thus a mapping between fields in the ISO ILL Request and the GEDI cover is made. This mapping will be formally defined in the next version of the GEDI agreement, which is being developed and expected to be published during 1997. The GEDI agreement is also being proposed for adoption by the ISO TC46 committee for publication as an ISO standard.

Z39.50 Item Order

Z39.50 is a standard for searching databases (such as bibliographic catalogues) which is gaining wide acceptance in the library community. The Z39.50 Item Order service uses a message which is closely based on the ISO ILL Request message, this is discussed in detail section 5.

JEDDS/Ariel DDIs

The JEDDS project [JEDDS] (see section 4.5) is developing an application for electronic document delivery and receipt using the GEDI agreement. The application is designed to interface automatically with an Interlibrary Document Request Management System (ILDRMS), by exchanging messages with the ILDRMS. As an example there will be a message to request sending a document, another message to inform the ILDRMS that a document has arrived and so on. These messages are called Document Delivery Instructions (DDIs). While developing the messages it became clear that they had close equivalents in the ISO ILL message set, so the project is in fact using ISO ILL APDU format messages as DDI messages. The project is suggesting that this specialised use of the ISO ILL APDUs might be adopted as an ISO profile or extension of the protocol.
4.3 Implementors Fora 

EWOS/EG-LIB

The European Workshop on Open Systems Expert Group on Library Applications (EWOS/EG-LIB) [EGLIB]has been the focus of European activities in developing the standard and ISO profiles for use with the standard. It has close links with ISO TC46/SC4/WG4 and the International Federation for Open Bibliographic Systems (IFOBS) and has worked closely with both of these groups. In 1995, in collaboration with the European Commission, DG XIII, the group started the European Forum for Implementors of Library Automation (EFILA)[EFILA] which holds regular meetings four times a year and brings together people from all over Europe to discuss implementation experiences and ways forward for development in all areas of automated library applications, in particular use of the ISO ILL standard.

IFOBS

The International Forum for Open Bibliographic Systems has active membership in the USA and Canada as well as Europe. It has worked with EWOS/EG-LIB to develop the standard and the ISO profiles. 

NAILDD IPIG
The North American Interlibrary Loan and Document Delivery Project (NAILDD), run by the Association of Research Libraries (ARL),  has set up an implementors group, now open to international membership, called  IPIG (ILL Protocol Implementors Group). The group is made up of organisations who are committed to implementing the protocol. Initially members were from the USA and Canada, but membership has now been widened to international membership. UK membership includes The British Library and Fretwell-Downing. The IPIG home page is at [IPIG], where a complete list of members may be found. It’s chair, Mary Jackson, gives a history of the group in [JACK1].

Work in the  IPIG includes
•	setting up the transponder (gateway) mentioned above (section 4.4)
•	setting up conformance testing facilities
•	work on a common profile to be used by all members
•	work on extensions to the protocol, e.g. patron description, authentication etc.
•	work on common item metadata such as System Identifiers
•	work on APDU (message)  transport mechanisms
•	work on directory services for use by implementations of the protocol

and the group is likely to submit proposals for changes to the protocol.

4.4 Service Environment

The standard defines the syntax and semantics of messages that may be used to carry out the interlending activity, and defines actions that must or might arise as a result of message receipt (state tables). It says nothing about the environment in which the protocol should be used, and whereas the protocol messages contain enough information for the complete management of requests and loans, it does not provide mechanisms for negotiating accounts and services at a supplying library, billing or payment, discovery of  the existence of the item or its location and circulation details, these must done outside of the protocol.

We have already seen that the protocol must, at the very least, be used through a user interface to a software application which has implemented the protocol or has access to an ISO ILL Protocol Machine amongst other modules (such as accounting, holdings searches etc.), but this can be in the context of different service environments. Joe Zeeman [ZEE] and Mary Jackson [JACK2] identify and describes in detail 11 scenarios in which ILL requesting might take place, most of them can utilise the ISO ILL protocol, sometimes in conjunction with Z39.50 Item Order or proprietary ordering systems. They may be summarised as follow

•	Point-to-Point ILL with a mediating library.
•	Here the patron will request an item at their local library, using local methods such as a form, phone call or local on-line system, and it is the library which will fully manage the inter library request. The library, having identified that the item must be ordered from a remote library, and identified the library, might use ISO ILL to request delivery of the item. Once the item arrives at the local library the patron is informed.
•	Point-to-Point with Forwarding. In this variation of the previous scenario the local library might send an ISO ILL request to a sequence of supplying libraries until the request is satisfied.

•	Document Supply via an ILL Utility.
•	In this model the Utility is acting as an intermediary in the ILL process, managing the InterLibrary loan on behalf of the patron’s local library. The interactions between the local library and the intermediary, and between the intermediary and one or more potential suppliers of the material (responders) could be by using the ISO ILL protocol. The Utility might give access to  holdings information to requesting library in order for it to have some control on which responders are accessed  (the LASER Viscount system is an example of such a model).
•	In an extension of the previous scenario the local library might have access to more than one ILL Utility to which it might send an ISO ILL request.

•	Patron Initiated ILL
•	The patron may have direct access to a remote responding library or library utility, being able to locate items through on line catalogues and holdings information. The patron might initiate a request for an item directly to the holding library or it’s intermediary. In this scenario the responding library (or intermediary) will seek authorisation from the patron’s local library before proceeding with the supply. Although interactions between the patron and the supplying library or intermediary may utilise the ILL protocol, the mediation between the supplying system and the local library is not catered for by the protocol and must happen using other messaging facilities, e.g. Z39.50 to search the local library’s client database. Alternatively a universal authorisation system must be set up against which individuals may be checked. 
•	This scenario might also be used where the remote library has reciprocal lending arrangements with the local library and simply informs the local library of the transaction.
•	To use the ISO ILL protocol to model the above scenario the patron would send the request to the local library, having obtained locations or citation information from a remote utility managing an on line catalogue. The local library may then mediate the request and forward it on to the utility or supplier. By using the chaining ISO ILL model the patron’s library will be able to manage the complete transaction.

•	Document supply using circulation knowledge
•	More complex scenarios may be envisaged, in the first of these the patron may have used a remote facility to discover an item (perhaps using Z39.50) and send an ILL request to their local library using Z39.50 Item Order. The local library might then use on line holdings and circulation information at potential suppliers (using Z39.50 searching) before selecting a supplier to whom to send an ILL request.
•	In a more fully integrated system (such as that being developed in the UNIverse and EDDIS projects) the patron may have access to a search and order client that automatically submits an item order to the local system once an item is discovered. The client will be interfacing a system that provides Z.39.50 searching facilities and either uses Z39.50 item order or ISO ILL ordering directly.

Item delivery, be it electronic or otherwise, happens outside of the protocol. The items might be delivered directly to the patron or via the patron’s local library. The protocol does provide messages for the supplying library and local library to exchange information about dispatch and receipt of the item.

Many libraries and suppliers of library systems have implemented their own proprietary electronic ILL systems, such as the British Library ART system or LASER Viscount system. It is impossible from an operational point of view to introduce a completely new system, such as ISO ILL, as a replacement for an existing system currently successfully supporting sometimes hundreds or thousands of clients. In these situations it is likely that the ISO ILL protocol will be available through additional modules that will interact with the existing system, as an example the British Library have been considering the feasibility of an ISO ILL gateway interface to the ART system and the new version of Viscount (Viscount 3) currently under development will include ISO ILL capability as well as maintaining existing facilities.
4.5 Implementations

Up until this time the ISO ILL protocol has mainly been in use by the National Library of Canada and other Canadian libraries, but the last two years has seen a marked increase in interest in the ISO ILL protocol amongst members of the library community. Partly this interest has been fuelled by publicly funded development projects which are committed to using acknowledged standards for interworking, but there is also a growing interest amongst organisations providing ILL services in being able to share resources and automate the process of item request and delivery and loan management by setting up interfaces to their systems that can accept requests using the ISO ILL protocol. A recent survey carried out by KPMG  for the European Commission concluded that suppliers of library systems were committed to implementing standards including ISO ILL and integrating them with their existing products [KPMG]. The NAILDD IPIG group was formed to foster implementation of the protocol with the USA and Canada [JACK1]. The remainder of this section lists a number of existing and planned implementations of the protocol.

Operational  and Commercially Available Systems

These are developed in Canada and use EDIFACT encoding over RFC822 e-mail to transmit messages.

•	National Library of Canada AMICUS system. This is currently being re-developed to use BER encoded messages. 
•	Network Support Inc.  Relais System has several modules including an ILL module which uses ISO ILL protocol.
•	ISM AVISO request management system incorporates ISO ILL requesting facilities.
•	TKM InterLend system.

Completed Projects

ION
Project ION (Interlending Open Systems Network)  set up a demonstrator ISO ILL network between participants in the Netherlands, France and the UK.  The project ran between 1990 and 1993. Participating organisations were LASER (UK) PICA (Netherlands) and MEN/SUNIST (France).
AIDA 
AIDA (Alternatives for International Document Availability) was a pilot project which set up Italian and Portuguese library networks providing international interlending and document supply services in Italy and Portugal. The project had partners in Italy, France and Portugal, the lead partner was Studio Staff Srl, Rome, the project ran between 1994 and 1995 [AIDA] .
DALI

The Document and Library Integration (DALI) project  [DALI] developed a service for multimedia document delivery over Z39.50  within a library-based infrastructure. As part of the project it implemented an ILL-based management and cost recovery service. It used the Z39.50 Item Order service to request documents, following on with the ISO ILL protocol running over TCP/IP to complete the item order/delivery process. The project ran from 1995 and finished in 1997.

The DALI project has submitted a profile for using the TCP/IP transport protocols to transmit ISO ILL APDUs, the profile has been submitted to EWOS/EG-LIB and to the IPIG [ILLTCP].
 
The co-ordinating partner was Fretwell-Downing Data Systems Ltd. (UK) other main partners were Institute of Oceanographic Sciences ( UK), University College Dublin (Ireland) and Computer Networks and Distributed Systems Research Group (CNDSRG) in the Department of Computer Science (Greece).

EDIL

The EDIL project set up an implementation of the GEDI model (Agreements of the Group on Electronic Document Interchange for Electronic Document Delivery) [GEDI]for document delivery between national libraries in France, Netherlands, UK and Germany. It used the ISO ILL protocol to transmit requests for scanned documents between the libraries using both X400 and RFC822 e-mail, encoding the PDUs in EDIFACT. The project ran from 1994 to 1996

Systems and Projects under development

eLib Projects

EDDIS
Electronic Document Delivery - Integrated Solution (EDDIS) will develop a server, comprising several interdependent hardware and software components, that a library may use to provide integrated information access services to it’s users. The server will facilitate searching, locating, ordering, electronic delivery, loan of returnable items and the management functions associated with these services.  The system will incorporate the ISO ILL protocol for the ordering and loan management services. The lead partner in the project is the University of East Anglia, other participants include University of Lancaster, University of Stirling, and BIDS (University of Bath). Started 1996

LAMDA 

The LAMDA project is setting up document requesting and delivery services amongst a number of UK libraries in the London and Manchester areas (10 supplying libraries and over 40 client libraries) and will be using the JEDDS Ariel station as described above. It will only be using the simple ISO ILL requesting mechanisms offered by the Ariel system, in other words it will not be using a full interlibrary loan management system or the full ISO ILL protocol.

JEDDS and RLG

The JEDDS project is funded by the Australian Vice Chancellors Committee with a special Government grant, and  is also funded by the eLib Programme. It is supporting the enhancement of the Research Libraries Group, California (RLG) Ariel GEDI document scanning and delivery station. Ariel will be enhanced to deliver documents using the MIME electronic mail protocol [MIME]. 

The system will also be able to receive and send ISO ILL Requests, although it will only implement a subset of the protocol and it’s messages. This is intended for use as an ILL requesting or supplying station for smaller libraries that will not have a complete ILDRMS system. The ILL messages will be BER encoded and transmitted by MIME e-mail and only ILL-REQUEST,  ILL-Answer, ILL-Shipped and ILL-Status-or-Error-Report services will be implemented.

It will receive scanning instructions and communicate the results of  the document delivery operation using Document Delivery Instructions (DDIs). Since the information needed for DDIs is almost identical to that present in ISO ILL messages it was decided to use the definitions of ISO ILL APDUs to also define DDIs, so that they become, in effect, a special use of the ISO ILL protocol. DDIs are not designed to interact with an ISO ILL protocol machine in any way. The JEDDS project has put forward a suggestion for a MIME mail format for transmitting ISO ILL APDUs which are BER encoded.

Partners in the project are the Australian Vice-Chancellors’ Committee, the National Library of Australia, the National Library of New Zealand and the Joint Information Systems Committee, (UK) (JISC) through the eLib programme.

RLG are also planning to add ISO ILL capability to their RLIN service.

UK Services

British Library

The British Library has been offering automated ILL request and management through its ART system since 1975, and now handles over 4 million requests every year. The ART system offers a number of access methods including electronic mail and terminal access over the Internet (ARTEmail and ARTTel). Meanwhile the British Library has been very actively participating in the development of the ISO ILL standard, and is a leading member in the UNIverse project and the EDIL project which finished in 1996 (see above).  It has been examining the feasibility of offering ISO ILL standard request and loan management messaging for access to its services, but recognises that it would be operationally difficult to simply replace existing access methods to the ART system with ISO ILL. It is therefor looking at the possibility of offering an ISO ILL interface into the ART system that would work along side other access methods. At the time of writing  no decisions have been taken, but there is every expectation that such a service will be offered. Meanwhile an ISO ILL service will be offered as part of the Library's participation in the UNIverse project to other project participants.

London and South Eastern Library Region (LASER)
LASER is an organisation that offers inter library loan facilities between member libraries in London and the counties in the south of England. It holds a union catalogue with about 3 million bibliographic entries (and 30 million locations), organises the transport of loaned items and offers automated requesting through its Viscount system, which now extends LASER's links to the Midlands, Yorkshire and Scotland. The Viscount system offers links to the British Library ART system. LASER participated in the ION project which set up a demonstrator ISO ILL system with links between the partners in the UK, Netherlands and France and now plans to install ISO ILL as an access standard for it's Viscount system (part of the Viscount 3 development being done by Fretwell-Downing) during 1997.
US Projects

OCLC
They are implementing ISO ILL Responder systems to integrate into their service, and have defined two extensions of specific use for their customers. They are using the Z39.50 AccessControlFormatPrompt-1 object to transmit user authentication information. They are also working on a project that will implement ISO ILL requestor role.

IPIG Transponder

The Library Corporation (LC) and Canada Institute of Scientific and Technical Information (CISTI) have developed a Transponder that will enable systems using different APDU encoding or different transport mechanisms to interwork. As an example the NLC use EDIFACT encoding and RFC822 e-mail so a system such as DALI would be able to send and manage requests to NLC only by sending the ISO ILL messages through the Transponder.  To do this the systems must use the extensions developed by TCL in each APDU to carry information about the requesting and responding systems, including APDU encoding, transport mechanisms and network address.

TRLN Document Delivery Project

Since 1993 Triangle Research Libraries Network (TRLN) have had a version of  the ISO ILL  protocol incorporated in their Document Delivery project.
The European Commission Telematics Applications Programme, funded by DG XIII, have supported a number of projects in the Libraries programme:
ELITE

This project started a year ago and aims to "develop a generic model for distributed library services to users including a detailed assessment of economic, organisational, managerial and technical options." The project will develop a prototype of the model for evaluation. It will be drawing on results from other projects including RAPDOC, AGADES, EDIL, ION, and  FASTDOC. It aims to examine these issues on a European scale. It will integrate information access services such as searching, ordering, delivery,  and billing, a number of reports will be written documenting the work. The co-ordinators are Telis, France, with participants including INIST (France), Beilstein Institut (Germany), PICA (Netherlands), University of Florence (Italy), University of Thessaloniki (Greece), Bibliothèque de l'Université René Descartes and Bibliothèque de l'Université de Lyon (France). Started in 1996.

UNIverse

Project UNIverse is a large scale project based on the concept of a virtual union catalogue for libraries. It aims to deliver and utilise a 'logical union catalogue' that is capable of providing a single point of contact for specific subject domains. UNIverse will use this logical union catalogue to deliver a number of advanced library services for both the end-user and the librarian. It will develop an interface that hides the physical distribution of information, its inevitable duplication, heterogeneity of storage and access methods and even language. It will include an Inter-Library Loans service integrated to the search and retrieve process using both Z39.50 Item Order service and the ISO ILL protocol (over both TCP/IP and e-mail transport protocols). UNIverse will exploit the outcomes of previous Library projects including the DALI project. Started in 1996.
The co-ordinating partner is Fretwell-Downing Data Systems Ltd (UK), other main partners are  Danish Technical Knowledge Centre, the British Library (UK),  Irish Library Council,  National Library of Greece, Freshwater Biological Association (UK), Southampton Oceanographic Centre (UK), Harper Adams College (UK), Kyros (Greece),  University College Dublin (Ireland), Q-Ray (Netherlands),  Ex-Libris  (Luxembourg),  University of Sheffield Library (UK), Index Data (Denmark),  Forbait (Ireland), The Technical University of Delft (Netherlands) and Technical University Library of Norway.

The ACTS programme of the European Commission is funding the GAIA project:
GAIA

The Generic Architecture for Information Availability (GAIA)  project will develop [GAIA] a sector and supplier independent architecture to support multilateral information trading which will facilitate location and delivery of information, content and digital services through a scaleable brokerage model, demonstrating the applicability of the model in three sectors - Music, Publishing and Technical Data. Delivery of information will utilise stream delivery technology as well as ‘packet’ delivery of such items as electronic or scanned documents. The order module will include an implementation of the ISO ILL protocol. Started 1996.

The co-ordinating partner is Fretwell-Downing Ltd (UK), other participating partners include, Codus Ltd (UK), National Centre of Popular Music (UK),  Computer Securities GAIA Technologies (Sweden), Danish Technical Knowledge Centre, Dialogue Communications Ltd (UK), FI Soft (Romania), Index Data (Denmark), Kyros (Greece), Nexor Ltd (UK) , Q-Ray (Netherlands), Sophora Ltd (UK), Teltec (University College Dublin - Ireland), University of the Aegean (Greece), University of Thessaloniki (Greece), North West Labs Ltd (UK), Screenphones Ltd (UK) and Warp Records (UK).

Projects in Germany

DBV-OSI II

The DBV-OSI II [DBV] project is now implementing version 3 of Z39.50 (Z39.50-1995) to offer users of  the abstract databases at DIMDI (medical information centre) Köln the ability to search the Zeitschriftendatenbank (union catalogue periodicals) and library catalogues of a number of regions, to copy bibliographic data between systems. Access to the bibliographic data and thesauri of the Deutsche Bibliothek will be offered this way.

Phase two of the project will look at ordering and delivery. Initially  ItemOrder of Z39.50 will be implemented for non returnable items followed by implementation of  the ILL protocol for request and tracking  of returnable items. partners include PICA and many German partners including Deutsches Bibliothek.

SUBITO

Subito is an initiative of German federal and regional governments to integrate search, ordering and delivery at the workplace of the user. It should help to further the use of research literature in industry. The project aims to give access to search, order and delivery services from the workplace using any kind of network connections. It relies on technical solutions provided by DBV-OSI. and has decided that the ordering interfaces of existing systems will stay alongside a newly developed services. Started 1994
A number of services of the ILL protocol have also been implemented in a related project at the University of Constance.

Activities in Australia

CILLA

The Co-ordinated InterLibrary Loan Administration Project (CILLA) will be developing a local interlending and document request management system (ILDRMS) which will handle all aspects of the administration and management environment found in interlending and document delivery operations used by the Australian library community, having completed an extensive study on the requirements of such a system [CILLA]. The system will use an open-systems approach and require compliance with international standards, including ISO ILL.

NSP

At the same time the Australasian National Library has intiated the Networkd Services Project (NSP), will be developing an integrated system for resource discovery, ordering and delivery that will interwork with CILLA systems. The NSP project is also committed to using open and internationally agreed standards within their systems, include ISO ILL.

4.6 References and URLs
[AIDA] Project AIDA  - http://www.cib.unibo.it/aida
[CILLA] CILLA feasibility report - http://www.gu.edu.au/alib/iii/docdel/cilla
 [DALI] Home page of the DALI project - http://dallas.ucd.ie:80/|dali/
[DBV] DBV-OSI II project home page -  http://www.ddb.de/projekte/dbv-osie.htm
       DBV-OSI II home page - http://www.ddb.de/projeckte/dbv-asie.htm

[DGXIII]  EC DGXIII Telematics Programme - http/www2.echo.lu/libraries/en/libraries.html

[EDIL] Home page for the EDIL project - http://www.inist.fr/accueil/edil.htm
[EGLIB] EWOS/EG-LIB  - http://www.ewos.be/index.htm
[EFILA] EFILA - http://www2.echo.lu/libraries/en/projects/efila.html
EFILA also maintain a mailing list, to join send a message to efila-request@dkuug.dk with a body 'subscribe efila <your name>'.
[GAIA] Home page of the GAIA project - http://www.syspace.co.uk/GAIA

[GEDI] Electronic Document Delivery, Towards Further Standardization of International Interchange. 
Agreements of the Group on Electronic Document Interchange (GEDI). Version 2.1 July 1995.  
fttp://lib.ua.ac.be/pub/gedi/

[ILL] ISO 10160  Information and documentation - Open systems Interconnection - Interlibrary Loan Application Service Definition . Second Edition 1996. Reference number ISO 10160:1996(E).

ISO 10161 nformation and documentation - Open systems Interconnection - Interlibrary Loan Application Protocol Definition . Part 1: Protocol specification. Second Edition 1996. Reference number ISO 10161-1:1996(E).

 Copies of the draft of version 2 may be found at http://www.nlc-bnc.ca/ifla/II/illprot.htm

[ILLRESOURCE] IFLA ILL Protocol Resources web page  http://www.nlc-bnc.ca/ifla/II/illprot.htm
[ILLTCP] Draft profile for use of ISO ILL over TCP/IP - http://dallas.ucd.ie.:80/|dali/ill-rfc.html

[IPIG] ILL Implementors Group (IPIG) home page - http://arl.cni.org/access/naildd/ipighome.html
ARLs home page - http://arl.cni.org/access/access.html includes a list of North American vendors implementing ISO ILL.

[JACK1] Overview of North American Interlibrary Loan Protocol Activities. Mary E. Jackson, Association of Research Libraries, Washington, DC, USA. 1997. Paper to be given at 1997 IFLA Conference workshop entitled ‘ILL Protocol Standard: Interlending in an Open Networked Environment’.

[JACK2] The Application of the ILL Protocol to Existing ILL Systems. Mary E. Jackson, Association of Research Libraries, Washington, DC, USA. 1997. Paper to be given at 1997 IFLA Conference workshop entitled ‘ILL Protocol Standard: Interlending in an Open Networked Environment’.

[JEDDS] JEDDS home page - http://www.gu.edu.au/alib/iii/docdel/jeddshom.htm

[KPMG] Report by KPMG on ILL implementation in Europe.
  http://ww2.echo.lu/libraries/en.kpmgfin1.html
[MIME] RFCs 2045 to 2049 describe the Multipurpose Internet Mail Extensions (MIME), they can be accessed at ftp://ds.internic.net/rfc
[UNI] Home page of the Universe Project - http://www.fdgroup.co.uk/research/universe

[ZEE] Interlending in the Emerging Networkd Environment: Implications for the ILL Protocol Standard (1995). J. C. Zeeman. UDT Series on Data Communication Technologies and Standards for Libraries. 
http://www.nlc-bnc.ca/ifla/VI/5/reports/rep8/rep8.htm