ISO 18626:2017

INTERNATIONAL ISO
STANDARD 18626
Second edition
2017-12
Information and documentation —
Interlibrary Loan Transactions
Information et documentation — Transactions de prêt interlibrairies
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Messages . 2
4.1 General . 2
4.2 Request . 3
4.3 Request Confirmation . 6
4.4 Supplying Agency Message . 6
4.5 Supplying Agency Message Confirmation . 8
4.6 Requesting Agency Message . 9
4.7 Requesting Agency Message Confirmation . 9
4.8 Complex Types .10
4.9 Closed Codes .11
4.10 Error Data .13
5 Format and transport .13
5.1 Format .13
5.2 Transport .13
5.2.1 Applications acting as initiators .14
5.2.2 Applications acting as responders.14
5.2.3 HTTP/HTTPS message headers.14
5.2.4 Data privacy protection.14
6 Conformance requirements .15
Annex A (informative) Information website .16
Annex B (informative) Open Codes .17
Annex C (informative) XML schemas .23
Annex D (informative) Guidelines — Use cases .24
Annex E (informative) Supplying library’s internal unique record ID .33
Bibliography .34
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 46, Information and documentation,
Subcommittee SC 4, Technical interoperability.
This second edition of ISO 18626 cancels and replaces the first edition (ISO 18626:2014), of which it
constitutes a minor revision.
The main changes compared to the previous edition are as follows:
— for requests adding RequestSubType, which together with the added StartDate, EndDate and
MultipleItemRequestId give the possibility to qualify requests to handle several copies, being for a
specific period and support transfer of requests.
iv © ISO 2017 – All rights reserved

Introduction
This document is intended to first supplement and eventually succeed the old ISO interlibrary lending
protocol (consisting of ISO 10160, ISO 10161-1 and ISO 10161-2). Unlike its predecessor, this document
is well suited to the modern, web-based technological environment which is based on XML and web
services. Another important difference between the two standards is that while the old standard is
based on a 1980s model of ILL transactions, its successor is based on and supports a much simpler
exchange of transactions.
ISO TC 46/SC 4 made an attempt to revise ILL standards in 2007. The chosen policy — careful revision
of the existing standard — failed, since for some SC 4 P members the revision was too radical, whereas
some other P members indicated that it was not thorough enough. In order to avoid a similar deadlock,
the SC 4 plenary meeting chose a different strategy in 2012. The committee shall keep the old standard
alive as long as necessary by, e.g. making the editorial changes needed. But SC 4 also decided to start
the development of a new, Web-enabled ILL standard.
The new standard specifies three simple messages: a request, a supplying library message and
a requesting library message. The protocol is stateless, which means that there shall be no need to
maintain the interconnected state tables in the client and server applications (and the connections to
the state tables in applications behind them). The new ILL protocol should be much easier to implement
than the old one, while still retaining the essential functionality of its predecessor.
This document is the first part of a more general strategic initiative to standardize resource sharing in
ISO/TC46/SC4. As part of this intention, the editors have aligned element names, transport and XML
schema with similar functions in ANSI/NISO Z39.83 NISO Circulation Interchange Protocol.
INTERNATIONAL STANDARD ISO 18626:2017(E)
Information and documentation — Interlibrary Loan
Transactions
1 Scope
This document specifies the transactions between libraries or libraries and other agencies to handle
requests for library items and the following exchange of messages.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2108, Information and documentation — International standard book number (ISBN)
ISO 3166-1, Codes for the representation of names of countries and their subdivisions — Part 1: Country codes
ISO 3166-2, Codes for the representation of names of countries and their subdivisions — Part 2: Country
subdivision code
ISO 3297, Information and documentation – International standard serial number (ISSN)
ISO 4217, Codes for the representation of currencies
ISO 8601, Data elements and interchange formats — Information interchange — Representation of dates
and times
ISO 10957, Information and documentation — International standard music number (ISMN)
ISO 15511, Information and documentation — International standard identifier for libraries and related
organizations (ISIL)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
agency
library (3.2), library-related organization (3.5) or other agencies such as an archive or a museum or a
commercial document supplier
3.2
library
organization, or part of an organization, the main aim of which is to maintain a collection and to
facilitate, by services of a staff, the use of such documents as are required to meet the informational,
research, educational or recreational needs of its users
3.3
requesting agency
agency (3.1), which may send requests for library items (3.6) and receive them from the supplying
agency (3.4)
3.4
supplying agency
agency (3.1), which receives requests for library items (3.6) and delivers them to the requesting
agency (3.3)
3.5
library-related organization
institution, company, consortium or other organization which handles ILL requests and/or receives
requested library items (3.6) on behalf of one or more libraries (3.2)
3.6
library items
books, journals, articles, music, etc. or copies of these in physical or digital format
4 Messages
4.1 General
This document specifies three messages and responses to them for handling interlibrary loan
transactions:
— Request (see Table 1) and Request Confirmation (see Table 2);
— Supplying Agency Message (see Table 3) and Supplying Agency Message Confirmation (see Table 4);
— Requesting Agency Message (see Table 5) and Requesting Agency Message Confirmation (see
Table 6).
Guidelines about the use of this document are given in Annex D with Tables D.1 to D.9. Remark that
these tables are just illustrations and do not cover all relevant utilization.
For Request, Supplying Agency Message and Requesting Agency Message, a confirmation message
is sent immediately (see 4.3, 4.5 and 4.7). The Request Confirmation message (see Table 2) is not a
positive or negative response to the request; it indicates only that the Request message has been
received. If the Request message contains problems, the Request Confirmation message shall include
Error Data (see 4.10).
Codes used in tables are as follows:
—  R Repeatable;
—  M Mandatory;
—  CT Complex Type;
—  OC Open Code List (i.e. Scheme Value Pair);
—  CC Closed Code List (i.e. the code list is part of the ILL standard);
—  SC Standard Code List.
Open Code Lists are predefined schemes, consisting of an enumerated list of possible values for a given
data element that should be supported by applications conformant with this document. The Open Code
Lists of values are not comprehensive and implementer groups may develop additional schemes for
these enumerated types to cover their implementation requirements. Thus, an application may choose
2 © ISO 2017 – All rights reserved

to support additional schemes for one or more Open Code Lists. Core lists of values to be supported by
all implementations are defined in Annex B.
Standard Code Lists are based on code lists published in standards or other normative documents.
New schemes and values may be added to the Open Code List as described in Annex B.
Complex Types are listed and defined in 4.8.
Closed Code Lists (see 4.9) are a normative part of this document and shall be supported by applications
conformant with this document. They are similar to Open Code Lists, except that Closed Code Lists of
values are expected to be relatively comprehensive and stable. Therefore, no online version of these
lists shall be made available. However, new closed code scheme elements and code values may be added
to the future versions of this document.
Date and time shall always be provided in the form YYYY-MM-DDThh:mm:ssZ as specified by ISO 8601.
When time is not significant, e.g. when a due date is given, use 23:59:59Z to indicate the time, for
example, 2013-05-15T23:59:59Z.
Use of the identifiers in Table B.1 shall be according to the referred standards: ISIL according to
ISO 15511, ISBN according to ISO 2108, ISSN according to ISO 3297 and ISMN according to ISO 10957.
Use of the symbols in Table 7 shall be according to the referred standards: currency symbol to ISO 4217,
region symbol to ISO 3166-2 and country symbol to ISO 3166-1.
4.2 Request
The Request contains information about the item and service requested.
The Request is sent from the requesting agency to the supplying agency.
The Request contains some or all of the following groups of data elements as shown in Table 1.
— Header: administrative information
— BibliographicInfo: details of the item being requested
— PublicationInfo: information about the publication
— ServiceInfo: details of the service being requested
— SupplierInfo: list of potential suppliers
— RequestedDeliveryInfo: where and how to send the item
— RequestingAgencyInfo: details about the requesting agency
— PatronInfo: details about the patron
— BillingInfo: how to charge the requesting agency
Table 1 — Request
Element Definition Codes
Header Administrative information M
SupplyingAgencyId Identification of supplying library M
(Complex Type AgencyId) CT
RequestingAgencyId Identification of requesting library M
(Complex Type AgencyId) CT
MultipleItemRequestId Identification of MultipleItemRequest
Table 1 (continued)
Element Definition Codes
Timestamp Date and time of the transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RequestingAgencyRequestId Requesting library’s request identification or number M
RequestingAgencyAuthen- Authentication in supplying library system of the requesting library CT
tication (Complex Type)
BibliographicInfo Bibliographic information about the requested item M
SupplierUniqueRecordId SupplierUniqueRecordId should be used for the supplying library’s
internal unique identifier for the requested item, acquired from a
preceding automatic holdings request. If this identifier is used, there
should be no other identifiers in BibliographicInfo.
More information can be found in Annex E.
Title Title of the requested item
Author Author of the requested item
Subtitle Subtitle of the requested item
SeriesTitle Title of the series
Edition Number of the edition
TitleOfComponent Title of the component part (e.g. article)
AuthorOfComponent Author of the component part
Volume Volume number
Issue Issue number
PagesRequested Page from and page to
EstimatedNoPages Expected number of pages
BibliographicItemId Identification of a physical or electronic object R
(Complex Type) CT
Sponsor Person or organization sponsoring the publication
InformationSource Description of where bibliographic information was found
BibliographicRecordId Identification of a bibliographic record CT
(Complex Type) R
PublicationInfo Information about the publication
Publisher Name of the publisher
PublicationType Type of publication OC
PublicationDate Date of publication.
For serials and serial articles, this should be the publication date of
the component part such as issue, not the date when the serial was
first issued.
PlaceOfPublication Place of publication, e.g. a city

ServiceInfo Information about the requested service M
RequestType Type of request (new, retry or reminder) CC
If no request type is specified, the default is "new".
RequestSubType Sub type to qualify the request R
CC
RequestingAgencyPrevious- Requesting agency’s previous request number when a retry is sent
RequestId with updated data based on ReasonRetry
4 © ISO 2017 – All rights reserved

Table 1 (continued)
Element Definition Codes
ServiceType Type of service. Values: Copy, Loan or CopyOrLoan. If Copy is M
requested, then the requesting library is interested only in a copy. If CC
Loan is requested, then the requesting library is interested only in a
loan. If CopyOrLoan is requested, then the requesting library is
willing to accept either a copy or a loan.
ServiceLevel Level of service OC
PreferredFormat Format of medium requested OC
NeedBeforeDate The request is not relevant after the stated date/time.
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
CopyrightCompliance The requesting library’s copyright compliance OC
AnyEdition Values Y or N. Yes for yes to any edition. No if only the specified
edition is acceptable.
StartDate Start date for a Booking (RequestSubType)
Ref: ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
EndDate End date for a Booking (RequestSubType)
Ref: ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
Note Human readable note
SupplierInfo When a request is sent to a brokering institution, the requesting library R
may provide a list of potential suppliers (in preference order)
intended primarily for requests sent to brokers, but may be used in
other circumstances as well.
SortOrder Value from 1 to 99 defining the order of preference of use
SupplierCode Code defining a potential supplier CT
(Complex Type AgencyId)
SupplierDescription Textual information about supplier
BibliographicRecordId Identification of a bibliographic record used CT
(Complex Type)
CallNumber Indication of the shelf position of the resource
SummaryHoldings Textual description of summary level holdings
AvailabilityNote Information about availability

RequestedDeliveryInfo A prioritized list of suggested delivery methods, each with its own R
delivery address
SortOrder Value from 1 to 99 according to the order
Address Description of the delivery address. CT
(Complex Type ElectronicAddress or PhysicalAddress)

RequestingAgencyInfo Details of the requesting agency
Name Name of the requesting agency
ContactName Name of contact. For example, ILL staff member
Address Description of how to contact the requesting agency CT
(Complex Type ElectronicAddress or PhysicalAddress) R

PatronInfo Details of the patron for whom the request is being made.
Only used according to 5.2.4.
Table 1 (continued)
Element Definition Codes
PatronId Identification of the patron
Surname Surname of the patron
GivenName First name of the patron
PatronType Type of patron OC
SendToPatron Only used with value “Y” if requesting library asks the supplying
library to send the requested resource directly to the patron
Address Description of how to contact the patron. CT
(Complex Type ElectronicAddress or PhysicalAddress) R

BillingInfo Information about how the requesting agency expects to be billed for
and pay for the item
PaymentMethod The preferred payment method OC
MaximumCosts The highest amount the requesting agency is prepared to pay for the CT
service.
(Complex Type Costs)
BillingMethod Preferred billing method OC
BillingName Name of person in finance department, etc.
Address Description of the billing address CT
(Complex Type ElectronicAddress or PhysicalAddress)
4.3 Request Confirmation
Table 2 — Request Confirmation
Element Definition Codes
Header Administrative information M
SupplyingAgencyId Identification of the supplying library CT
(Complex Type AgencyId)
RequestingAgencyId Identification of the requesting library CT
(Complex Type AgencyId)
Timestamp Date and time of the confirmation transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RequestingAgencyRequestId Requesting library’s request identification
TimestampReceived Date and time of the confirmed request transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
MessageStatus Value “OK” or “ERROR” M
ErrorData If there are any errors, an error message is included; refer to 4.10.
4.4 Supplying Agency Message
Supplying Agency Message is a message sent from the supplying library to the requesting library.
The message may be in response to a request or a message from the requesting library or a message
initiated by the supplying library. In all these cases, the same message is used.
The message contains the following groups of data elements as shown in Table 3.
— Header: administrative information
— MessageInfo: responses and notes
6 © ISO 2017 – All rights reserved

— StatusInfo: current status; i.e. status after any changes because of the message being sent
— DeliveryInfo: information about the shipped item
— ReturnInfo: if the supplier asks the requesting library to return the item to another address
Table 3 — Supplying Agency Message
Element Definition Codes
Header Administrative information M
SupplyingAgencyId Identification of the supplying library M
(Complex Type AgencyId) CT
RequestingAgencyId Identification of the requesting library M
(Complex Type AgencyId) CT
Timestamp Date and time of the transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RequestingAgencyRequestId Requesting library’s request identification or number M
SupplyingAgencyRequestId Supplying library’s request identification or number

MessageInfo Message from the supplying library to the requesting agency M
ReasonForMessage A code defining the reason for the message M
CC
AnswerYesNo Values Y or N – for Yes or No to respond
Mandatory when ReasonForMessage is RenewResponse or
CancelResponse
Note Human readable note
ReasonUnfilled The reason why the request cannot be filled OC
ReasonRetry The reason why the request cannot be filled unless it is modified or OC
repeated at a future date
OfferedCosts Applied when ReasonRetry is used because actual costs exceed the CT
MaximumCosts of the requesting library. The supplying library
indicates what the actual cost shall be.
(Consists of Complex Type Costs)
RetryAfter The date and time after which the retry request may be sent.
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RetryBefore Date and time before which to send the retry request.
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ

StatusInfo Status information M
Status Actual status of the request in the supplying library M
CC
ExpectedDeliveryDate Date and time the supplying library expects to deliver the item.
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
DueDate Date and time the item is expected to be back at the supplying library.
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
LastChange Date and time of the last status change M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ

Table 3 (continued)
Element Definition Codes
DeliveryInfo Information about the delivery
DateSent Date and time when the item was sent M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
ItemId Value of Barcode or RFID-tag Id of the item being delivered
SentVia The service via which the requested item was sent OC
SentToPatron Value “Y” if the supplying library has sent the item directly to the
patron and value “N” if the supplying library has not sent the item
directly to the patron despite the fact that the requesting library
asked for this service. (see Request: SendToPatron)
LoanCondition Conditions for use of the item OC
DeliveredFormat Format of the delivered item OC
DeliveryCosts Amount the supplying library is charging the requesting library for CT
the item and related service
(Complex Type Costs)
ReturnInfo If the Supplier asks the Requester to return the item to another address
ReturnAgencyId Identification of the library to which the item should be returned CT
(on request of the supplying library)
(Complex Type AgencyId)
Name Name of the library to which the item should be returned.
PhysicalAddress Address to which the item is to be returned CT
(Consists of Complex Type PhysicalAddress)
4.5 Supplying Agency Message Confirmation
Table 4 — Supplying Agency Message Confirmation
Element Definition Codes
Header Administrative information M
SupplyingAgencyId Identification of the supplying library CT
(Complex Type AgencyId)
RequestingAgencyId Identification of the requesting library CT
(Complex Type AgencyId)
Timestamp Date and time of the confirmation transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RequestingAgencyRequestId Requesting library’s request identification
TimestampReceived Date and time of the confirmed Supplying Agency Message M
transaction
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
MessageStatus Value “OK” or “ERROR” M
ReasonForMessage ReasonForMessage in confirmed Supplying Agency Message CC
ErrorData If there are any errors, an error message is included; refer to 4.10.
8 © ISO 2017 – All rights reserved

4.6 Requesting Agency Message
Requesting Agency Message is a message from the requesting library to the supplying library.
The message contains the following groups of data elements as shown in Table 5.
— Header: administrative information
— ActiveSection: elements describing what to do
Table 5 — Requesting Agency Message
Element Definition Codes
Header Administrative information M
SupplyingAgencyId Identification of the supplying library M
(Complex Type AgencyId) CT
RequestingAgencyId Identification of the requesting library M
(Complex Type AgencyId) CT
Timestamp Date and time of the transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RequestingAgencyRequestId Requesting library’s request identification or number M
SupplyingAgencyRequestId Supplying library’s request identification or number
RequestingAgencyAuthen- Authentication in supplying library system of the requesting library CT
tication (Complex Type)
ActiveSection Elements describing actions M
Action An action for the request M
CC
Note Human readable note
4.7 Requesting Agency Message Confirmation
Table 6 — Requesting Agency Message Confirmation
Element Definition Codes
Header Administrative information M
SupplyingAgencyId Identification of supplying library CT
(Complex Type AgencyId)
RequestingAgencyId Identification of requesting library CT
(Complex Type AgencyId)
Timestamp Date and time of the confirmation transaction M
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
RequestingAgencyRequestId Requesting library’s request identification
TimestampReceived Date and time of the confirmed Requesting Agency Message M
transaction
Ref. ISO 8601
Format: UTC: YYYY-MM-DDThh:mm:ssZ
MessageStatus Value “OK” or “ERROR” M
Action Action in confirmed Receiving Agency Message CC
ErrorData If there are any errors, an error message is included; refer to 4.10.
4.8 Complex Types
A Complex Type is a set of information linked together describing, for example, identification with type
and value, as shown in Table 7.
Table 7 — Complex Types
Element Definition Codes
AgencyId Identification of the supplying library or the requesting library
AgencyIdType Type of identifier for the library OC
AgencyIdValue Value of the identifier for the library

BibliographicItemId One or more unique standard identifiers (from different
identifier systems) for the requested resource
BibliographicItemIdenti- Type of bibliographic item identifier OC
fierCode
BibliographicItemIdentifier A unique identifier for the item (e.g. the ISBN)

BibliographicRecordId One or more unique identifiers (from different identifier systems) for the
record related to the requested resource
BibliographicRecordIdenti- Type of bibliographic record identifier OC
fierCode
BibliographicRecordIdenti- A unique identifier for the record (e.g. the OCLC record number or LC
fier control number)
Costs The cost for the request
CurrencyCode Currency symbol as specified in ISO 4217 SC
MonetaryValue Amount of money
ElectronicAddress Electronic address
ElectronicAddressType Type of electronic address OC
ElectronicAddressData Value of the electronic address

RequestingAgencyAuthen- Authentication in supplying library system of the requesting library
tication
AccountId The customer number in supplying library database of other libraries
SecurityCode Password, PIN code or similar function.

PhysicalAddress Mailing address
Line1 Address – first line
Line2 Address – second line
Locality Locality of the library/agency or the contact person
PostalCode Postal code according to the rules of the country
Region Region symbol as specified in ISO 3166-2 SC
Country Country symbol as specified in ISO 3166-1 SC
10 © ISO 2017 – All rights reserved

4.9 Closed Codes
Closed code elements and code values, as shown in Table 8, are vitally important to the Interlibrary
Loan protocol. All of them shall be supported by applications conformant to this document.
Table 8 — Closed Codes
Elements Code values Description
RequestType New The requesting library sends a new request.
Retry The requesting library sends the request again based
on status RetryPossible.
Reminder The requesting library sends the request again with
the intention to remind the supplying library about the
request.
RequestSubType BookingRequest Request for a specific period. Used together with
StartDate and if relevant, an EndDate
MultipleItemRequest Bundle up more than one request for same
bibliographic item
PatronRequest Insertion of a patron initiated request from a patron
OPAC or search portal to the patron's local ILL system
TransferRequest Intermediary service: Handover of management of an
ILL request from one ILL system to another
SupplyingLibrarysChoice A service defined by the supplying library, which the
requesting library can select.
ServiceType Copy The requesting library asks for a copy of the
requested item.
Loan The requesting library asks for a loan.
CopyOrLoan The requesting library accepts both a copy and loan of
the requested item.
ReasonForMessage RequestResponse Supplying library answers a request.
StatusRequestResponse Answer to the action StatusRequest from the
requesting agency.
RenewResponse Answer to the action Renew from the requesting agency.
CancelResponse Answer to the action Cancel from the requesting
library.
StatusChange The supplying library indicates a change of status
without receiving a request to do so from the
requesting library. The new status must be selected
from the status element list of values.
Notification The supplying library is sending a message to the
requesting library
Action StatusRequest The requesting library asks the supplying library to
provide the current status for the request.
Received The requesting library notifies the supplying library
the requested item has been received.
Cancel The requesting library asks the supplying library if the
requested item may be cancelled.
The supplying library returns a
SupplyingAgencyMessage with
ReasonForMessage = CancelResponse Yes or No.
Table 8 (continued)
Elements Code values Description
Renew The requesting library asks the supplying library if the
item currently on loan may be renewed.
The supplying library returns a
SupplyingAgencyMessage with
ReasonForMessage = RenewResponse Yes or No
(and DueDate if applicable).
ShippedReturn The requesting library notifies the supplying library
that the borrowed item has been sent back.
ShippedForward The requesting library notifies the supplying library
that the borrowed item has been returned and sent to
the library specified in ReturnInfo.
Notification The requesting library sends a message to the
supplying library.
Status RequestReceived Supplying library has received the request.
ExpectToSupply Supplying library expects to fill the request, based on
e.g. information in the local OPAC.
The message may include the ExpectedDeliveryDate.
WillSupply Supplying library has located the item but has not
sent it yet.
Loaned The item is currently on loan to the requesting library
for this request.
Overdue The item currently on loan to the requesting library for
this request is now overdue.
Recalled The item currently on loan to the requesting library for
this request has been recalled.
RetryPossible The supplying library cannot fill the request based on
information provided or may be able to supply at
a later date. The explanation may be provided in the
ReasonRetry data element. The Requesting library may
submit a modified request with revised ServiceLevel
or MaximumCost, etc.
Unfilled The supplying library cannot fill the request. The
explanation may be provided in the ReasonUnfilled
data element.
CopyCompleted The supplying library has sent the requested item (this
status is used when there is no need to return the item
supplied).
LoanCompleted The supplying library has received the borrowed item
from the requesting agency (this status is used for
requests when the item supplied shall be returned by
the requesting library, i.e. a loan)
CompletedWithoutReturn The supplying library has closed the request without the
return of supplied item, e.g. because of loss or damage.
Cancelled The supplying library has cancelled the request (as
indicated by the requesting library).
12 © ISO 2017 – All rights reserved

4.10 Error Data
If the supplying library or the requesting library or the ILL applications used by them are not able to
process a request or a message, the receiving ILL application should respond with Error Data, as shown
in Table 9, incorporated in the Confirmation Message.
Table 9 — Error Data
Element Definition Codes
ErrorData One of following errors M
UnsupportedActionType The supplying library cannot handle the received message
because the Action in Requesting Agency Message is not
supported.
Value: Action type which is not supported by the application
UnsupportedReasonforMessageType The requesting library cannot handle the received
message because the ReasonforMessage in the Supplying
Agency Message is not supported.
Value: ReasonforMessage Type which is not supported by
the application
UnrecognisedDataElement The supplying library or requesting library has received a
data element it does not recognize.
Values: Data Element which is not recognized by the
application
UnrecognisedDataValue For data elements with code lists, the receiving system
may respond with an error message if the code or
combination of codes is not recognized.
Value: The combination of the name of the Data Element
and the Element Values or combination of Elements Values
which is not recognized by the application
BadlyFormedMessage The structure of the incoming message did not conform to
the protocol schema definition and could not be
interpreted by the receiving system
No Value.
5 Format and transport
5.1 Format
The format of all messages is described in an XML schema. The schema is described in Annex C.
5.2 Transport
Implementations that conform to this document must behave in the following manner in regard to the
selection and use of transport protocols.
The Requesting Agency acts as initiator sending the Request or Requesting Agency Message. In these
cases, the Supplying Agency acts as responder sending the appropriate Confirmation Message.
The Supplying Agency acts as initiator sending the Supplying Agency Message. In these cases, the
Requesting Agency acts as responder sending a Confirmation Message.
NOTE The transport of messages is inspired by NCIP (see Reference [7]) which uses the transport method
described in RFC 2616.
5.2.1 Applications acting as initiators
Applications acting as initiators must support at least one of the following transport protocols:
— HTTP;
— HTTPS.
5.2.2 Applications acting as responders
Applications acting as responders must support all of the following transport protocols:
— HTTP;
— HTTPS.
The selection of the transport protocol by the initiator of a message dictates the transport protocol
used by the responder. The responder must respond using the same connection and therefore, the same
transport protocol that was used by the initiator.
All ISO 18626 messages sent via HTTP or HTTPS must use the POST method as specified in the version
1.1. of the Hypertext Transfer (HTTP) protocol (RFC 2616), thus:
POST http://illtransactions.org HTTP/1.1 CRLF

All ISO 18626 response messages sent via HTTP or HTTPS must use the normal HTTP/HTTPS protocol
response mechanism used to respond to POSTs. For example:
HTTP/1.1 200 OK CRLF
CRLF CRLF

5.2.3 HTTP/HTTPS message headers
For both optional ISO 18626 initiation and response messages, the HTTP/HTTPS Content-Type and
Content-Length headers must be included and coded as follows:
Content-Type: application/xml; charset="utf-8" CRLF
Content-Length: nnnn CRLF
Where nnnn is the length of the data being sent (not including the length of the message headers).
The entity transferred via the HTTP message must contain the entire text of the message following a
carriage return/line feed (CRLF) with no preceding text, thus:
CRLF
|

Where < initiation message > or < response message > contains the XML formatted data
(see 5.1) for the message being sent.
5.2.4 Data privacy protection
The Request message provides an option to include information about the patron for whom the item is
being requested.
Both the requesting and supplying agencies shall observe appropriate regulations (whether they are
international, national, regional or local in scope) regarding the privacy and protection of patron data
when PatronInfo is transferred or stored.
14 © ISO 2017 – All rights reserved

6 Conformance requirements
A local application in the Supplying Agency is conformant to this document if it supports the receipt of
Requests and Messages. A local application in the Requesting Agency is conformant if it supports the
receipt of messages as described in 4.2, 4.3 and 4.4 using the format and transport method as described
in 5.1 and 5.2.
If a Request or a Message includes actions which cannot be processed by the local application at the
supplying agency, the local application in the supplying agency or the requesting agency shall respond
with the relevant Error code in the Confirmation Message.
A local application in the supplying agency shall support at least two statuses.
Annex A
(informative)
Information website
A website with additional information about this document is available at:
http://illtransactions.org.
16 © ISO 2017 – All rights reserved

Annex B
(informative)
Open Codes
B.1 General
Open Code data elements and their identifiers (URIs) are listed in B.2. Values for these data elements
are specified in Table B.1. For instance, there are five values for the BillingMethod.
New data elements or data element values to existing data elements may be added as required by the
implementers and users of the protocol. In order to foster adoption of these extensions to the document,
an up to date version of
...