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Cataloging Distribution Service

The Library of Congress > Cataloging Distribution Service > MARC Distribution Services Ordering Instructions


Ordering Instructions

Please be sure to read all of the information in the tabs above this paragraph. To order a MARC Distribution Service (MDS), complete the FTP Registration/Order Form. Select the MDS service(s) you desire from the list embedded in the order form.

The Registration/Order Form asks for information about your host computer. All the information requested is required. If you have previously registered for MDS via FTP and all information concerning the host computer is the same, please designate your customer number and host Internet address.

Technical notices and further communications will be emailed to all contact person(s) designated on the Registration Form above.


Records in the MARC Distribution Services originating with the Library of Congress are copyrighted by the Library of Congress for use outside the United States. Subscribers are granted copyright permission to selectively redistribute records outside the United States; contact LC prior to any distribution.

CDS Customer Satisfaction Survey (CDS Survey). Please take this brief survey to help us serve you better.

Background Information

What is the MARC Distribution Service?

MDS is a family of bibliographic database products made available by the Library of Congress Cataloging Distribution Service (CDS). Included are Library of Congress MARC 21 bibliographic and authority records as well as U.S. Copyright Office records.

Posting and Retrieving of Records

MDS products are available via File Transfer Protocol (FTP) on a subscription basis, with issues made ready at daily and weekly frequencies. CDS provides a "Pick-Up" service for customers to retrieve files directly from our server. You will be assigned a logon id and password. You must provide CDS with your IP address as this will be authenticated during the logon process. Access is made in NON-passive mode only.

Getting Started

  • Complete the MARC Distribution Service FTP registration/Order Form. Email, fax, and mailing information can be found at the bottom of the order form.
  • CDS provides FTP instructions. This includes the Internet address, logon id, password and accessible directory. Files are routintely made available for 90 days.
General Information
  • Records are available in MARC8, UTF8 and/or MARC XML formats.
  • The "label" file and "records" file are both FTPed in binary mode. The "report" file is FTPed in ascii mode.
  • Retrospective records are generally segmented into smaller files due to their large size.

Available Files

All currently available MDS files (i.e., test, retrospective, subscription, and replacement) are available via FTP. Larger files, those exceeding 500 MB and most notably the retrospective files are segmented for FTP. Segment size can be modified dependent on receipt system's capabilities. Contact CDS to arrange for the FTP of large files.

Record, Report, Label, and Notice Files

Three files are issued for each subscription issue. A 'label' file identifies the file and adheres to the standard for FTP File Label Specifications for MARC21 Records. The 'record' file contains the MARC21 data. The 'report' file contains a listing of the records in the issue and a totals/statistics report. Because of their size, no report files accompany retrospective files.

The 'record' file has a file name of:

/<product directory>.<volume>.<issue or date>.records

Ex. /emds/books/eng.v23.i01.records

'Record' files are issued in three different formats. Records issued in the MARC8 character set have a file name extension of '.records', e.g., v30.i10.records. Records issued in the UTF8 character set have a file name extension of '.records.utf8', e.g., v30.i10.records.utf8. Records issued in the MARC XML format have a file name extension of '.records.xml', e.g., v30.i10.records.xml.

Note: The Books Daily file does not carry the volume and issue numbering but instead contains the date the file was created in a yy mm dd configuration.

The 'report' file has a file name of:

/<product directory>.<volume>.<issue or date>.report

Ex. /emds/books/

The 'label' file has a file name of:

/<product directory>.<volume>.<issue or date>.label

Ex. /emds/books/eng.v23.i01.label

Note : The Label File description gives the full specifications and an example of the label file used by CDS.

Periodically, CDS will issue technical notices and announcements that contain important information for MDS subscribers. They typically include details about new or changed MARC data elements, LC practice, or new programs. Notices are also emailed to the technical services contact person as designated in the FTP registration /Order form. All CDS notices will be available via FTP with a file name of:

/<product directory>.notice.d<issue or date>

Ex. /emds/books/eng.notice.d011001

The preceding file name format reflects the naming conventions used to store the files on the LC Server. This is the file name that the customer will retrieve from the CDS host.

Pricing and Frequency

The daily and weekly MDS files are available via FTP. The price is designated for each MDS.

Switching from MDS-Books (All) Weekly to MDS-Books (All) Daily

For an additional cost, MDS-Books (All) customers can subscribe to MDS-Books (All) Daily. Customers can initiate a Books (All) Daily subscription by requesting it on the Registration/Order Form. This service allows customers to receive the Books file on a more frequent basis. Connection and logon to the CDS server mainframe is the same for the Daily service as for the others; specifying the directory and file is the only difference. The startup of the Daily file will have to be carefully coordinated so that it commences immediately following a weekly distribution issue. CDS technical support staff are available to work with individual customers to test MDS-Books (All) Daily and insure a logical transition from the weekly to the daily service.

Technical Support

CDS will work with each customer individually to set up and test FTP. During normal working hours, CDS Technical support will be available to answer questions about system access, and to respond if or whenever an FTP transfer fails.

Library of Congress
Office of Business Enterprises
Cataloging Distribution Service
Washington, D.C. 20540-4910 USA

Telephone (Customer Support): 202-707-6100
Toll-free within the U.S.: 1- 855-266-1884
Fax (Customer Support): 202-707-1334

Label File Description

The full specifications for the standard for Electronic Transfer Label Files can be found in Specifications for Record Structure, Character Sets, and Exchange Media available by purchase from the Cataloging Distribution Service or by free download. Below is a brief description and example of the label file used by CDS in the FTP of the MARC Distribution Services.


The label file is written using only ASCII Latin characters. Each field in a label file begins with a three-character tag followed by two blanks (ASCII character 20(hex)). The field's data content follows the two blanks. Each field ends with an end-of-field marker (ASCII control character 1E(hex)) immediately following the data in the field.

DAT (Date compiled): This is the date and time the originating system completed the compilation of the file of records; the data is constructed in a YYYYMMDDHHMMSSF configuration
RBF (Number of records in file): Includes the number of logical records contained in the file
DSN (Data Set Name): The file name of the record file
ORS (Originating System ID): The name of the system that compiled the file
DTS (Dates Sent): The date of transmission of the file; the data is constructed in a YYYYMMDDHHMMSSF configuration
DTR (Dates of records): Includes inclusive dates-of-last-transaction of the records in the file, i.e. the first and last date recorded in the 005 fields of the file of records; the data is constructed in a YYYYMMDDYYYYMMDD configuration
FOR (Format): Designates the format of the records. M is for MARC
DES (Description of records): Describes the records, includes the product name
VOL (Volume): Gives the volume number of the subscription year
ISS (Issue): Gives the issue number of a volume
REP (Reply to): Contains the phone number and email address to contact in the event of problems or questions in transmission
NOT (Note): Contains textual information or messages about the file
Example of CDS Label File:
DAT 19960321124009.7
RBF 0003934
ORS LC Cataloging Distribution Service
DTS 199603211240097
DTR 1996022219960320
VOL = 13
ISS = 03
REP HELPDESK PH: 202-707-1260

NOT FAX : 202-707-7259 EMAIL: