March 2003 Revision:

This document gives guidelines on the use of field 856 and is current as of March 2003.  It includes all changes made to the field through the midwinter ALA conference held in January 2003.  It supersedes the August 1999 edition of the guidelines.

A description of the full field is available in MARC 21 Format for Bibliographic Data, field 856.  It is also available in the MARC 21 authority, holdings, classification and community information format documentation.



General Information

Specific Data Elements

URIs in Other Fields and Formats

LC Usage

Major Changes Included



Field 856 in the MARC 21 bibliographic, holdings, authority, classification, and community information formats is used for electronic location and access information to an electronic resource.

The field may be used in a bibliographic or holdings record for a resource when it or a subset of it is available electronically.  In addition, it may be used to locate and access an electronic version of a non-electronic resource described in either the bibliographic record, a portion of the resource described, or a related electronic resource.  See the Field 856 in Other Formats section for information about how field 856 is used in the authority, classification, and community information formats.

For the list of elements in field 856, see the table in:  856  Electronic Location and Access.


The data in field 856 may be a Uniform Resource Identifier (URI), which is recorded in subfield $u.  The necessary locator information may also be parsed into separate defined subfields.  Note that separate subfields for locator data was provided when this field was first established in 1993, but generally, these are seldom used.  An access method, or protocol used, is given as a value in the first indicator position (if the access method is email, FTP, remote login (telnet), dial-up, or HTTP) or in subfield $2 (if the access method is anything else).  The access method is the first element of a URL.  The field may also include a Uniform Resource Name or URN (e.g., a DOI (Digital Object Identifier) or handle).

See Multiple 856 fields below for guidelines on repeatability.

Topics in this section:

Uniform Resource Identifier

Required subfields

Encoding non-MARC characters

Multiple 856 fields

Field 856 in bibliographic or holdings records

Uniform Resource Identifier:

For any access method, a Uniform Resource Identifier (URI) is generally recorded in subfield $u.  Separate subfields may be used if it is desirable to display data in a particular way.

The most commonly used data elements in field 856 are as follows:

1st indicator = 4 for HTTP (earlier records may use blank)

Subfield $u = [HTTP URL]

Subfield $3 = data specifying to what the URI refers, if applicable

Subfield $z  = data relating to the electronic location of the source that is adequate for public display

Required subfields:

A URI in subfield $u is required unless electronic location and access information is parsed into separate subfields, in which case no single subfield is required.  When using this technique, the subfields used largely depends on the access method indicated in the first indicator or in subfield $2 (if first indicator = 7).

Encoding non-MARC characters:

In February 1994, Proposal 93-10 defined additional characters in the MARC character set to both accommodate existing bibliographic needs and to align it with the ASCII and ANSEL character sets.  Both the spacing underscore and the spacing tilde were added at the time because of the need in directory and file names for electronic resources.  Many systems have implemented these characters (see for more information about LC's implementation).  For systems that have not implemented the spacing underscore and tilde, the following alternative characters may be used:

spacing underscore:  %5F

spacing tilde:  %7E

Since these characters are valid ASCII strings, the above method allows for the functionality supported by Z39.50 clients and Web browsers which permit users to click on links to access resources represented by URLs.  When the additions to the MARC 21 character set are implemented to support the encoding of the spacing characters, it will be possible to replace all instances of %xx strings.

Multiple 856 fields:

There are many reasons to include multiple 856 fields in records.  The following are the most common:

Location data elements vary (the URI in subfield $u or subfields $a, $b, $d, when used)

Different access methods (e.g. a document available through HTTP and from an FTP server)

Different parts of the item are electronic, using subfield $3 to indicate the part (e.g. table of contents accessible in one file and an abstract in another)

Mirror sites (the same resource is made available at two different locations, often to facilitate access, perhaps internationally)

Different formats/resolutions (e.g. the ASCII version of an electronic journal vs. the Web home page for that journal; a thumbnail vs. archival copy of a digitized photograph)

Related items, using subfield $3 and second indicator value to specify

See also under subfield $u for repeatability guidelines.

Field 856 in bibliographic or holdings records:

Since field 856 is valid in both bibliographic and holdings records, institutions may favor recording it in the holdings record.  It is intended to be an electronic equivalent to field 852 (Location), which contains information used to identify the holding organization and other detailed information required to locate a physical item in a collection.  In early 1999, the Network Development and MARC Standards Office elicited opinions on whether it is desirable to use the field in bibliographic or holdings records.  Responses received generally favored recording the field in the holdings record where practical.  However, for a variety of reasons, such as the wider exchange of bibliographic records, many institutions use the bibliographic record despite the benefits of using holdings records.

The following advantages of using holdings records have been expressed:

Ownership to an electronic resource may vary by institution.  Such access information belongs in local holdings.

The holdings record is a means to bring together various versions.

Use of a single record approach for the bibliographic item has been implemented widely.  This practice makes it clearer to use holdings for the specific versions.

Having a hot-linked 856 field in holdings forces users to think of it as holdings information, and to separate information about the universal bibliographic item.

The "universal URL" that is for general access and any general information on access in note fields should be in the bibliographic record.  Specific local access URLs should be in holdings (although this may result in unpredictability).

Bibliographic field 856 might usefully be limited to links that do not apply to the entire bibliographic item (e.g., finding aid, table of content, abstract).

In order to move towards this approach in the future, it will be necessary to persuade vendors to make the following changes to their ILS systems:

Allow for hot links from holdings records

Allow for the ability to do link checking from holdings records

Provide indexing of holdings records

Allow for the ability to export the fields from holdings, to be exchanged either as separate holdings records or embedded in an exported bibliographic record

Provide for more logical displays of bibliographic/holdings information where necessary

Allow for sequencing multiple holdings records

At this point, it is a local decision whether to use the field in bibliographic or holdings records.


Topics in this section:

First indicator (Access Method)

Second indicator (Relationship)

Subfield $3 (Materials specified)

Subfield $q (Electronic format type)

Subfield $u (URI) repeatability

Subfield $y (Link Text)

Subfield $z (Public Note)

First indicator (Access Method):

The first indicator contains information about the access method to the resource and has values defined for email, FTP, Remote login (Telnet), Dial-up, and HTTP.  Access methods without defined values may contain a first indicator value 7 with the method indicated in subfield $2.  Older records may contain value 7 and subfield $2 (with content http) if created before value 4 (HTTP) was defined.

This list of indicator values and the values used in subfield $2 is specified in the URL standard (RFC1738) and maintained by the Internet Assigned Numbers Authority (IANA).  Additional schemes are documented by IANA in URI schemes.

For those access methods that have an indicator value defined (ftp, telnet, electronic mail), the URI is included in subfield $u with the appropriate indicator value recorded, even though it is redundant with the first element of the URI.

Value # (blank) (No information provided) may be used if only a URN (Uniform Resource Name) is recorded in subfield $u.  If using a URI in subfield $u with one of the access methods that has a value defined in the first indicator, the access method may be repeated in subfield $2, if desired (e.g. 856 0# $ $2mailto).

Value 7 and subfield $2 is used for electronic access to host-specific file names (i.e., files stored locally) with the access method, "file."  This designation is also a defined URI scheme.

Second indicator (Relationship):

A second indicator is provided to show the relationship between the information in field 856 and the resource described in the record.  This may be used for the generation of a display constant or for ordering multiple 856 fields.  For further information, see Proposal No. 97-1 (Definition of Second Indicator (Relationship to Source) in Field 856 in the MARC Formats).  Suggested display constants for the indicator values are:

# (blank)

Electronic resource:


Electronic resource:


Electronic version:


Related electronic resource:


[no display constant generated]

Subfield $3 (Materials specified):

Subfield $3 is used to specify to what portion or aspect of the resource the electronic location and access information applies.  Specific situations may be:

A portion or subset of the item is electronic.

Example:  $3table of contents; $3v. 2-5; $3abstract; $3b&w copy negative

A related electronic resource is being linked to the record.

Example:  $3author's self-portrait

Subfield $q (Electronic format type):

Subfield $q was originally defined as File transfer mode to include "binary" or "ascii."  It was redefined in June 1997 as Electronic format type to accommodate an Internet Media Type (MIME type), such as text/html.  Alternatively, textual information about the electronic format type may also be recorded.  See LC Usage for a description on how LC has used subfield $q in the American Memory project.

Subfield $u (URI) repeatability:

Subfield $u may be repeated only if both a URN and a URL or more than one URN are recorded.  Field 856 is repeated if more than one URL needs to be recorded.  Some institutions may wish to record a persistent name (URN) as well as a resolvable HTTP URL in field 856.

Example:  856 7#$dsawmp$f1694$u

Persistent Uniform Resource Locators (PURLs) at OCLC are intended to deal with the problem of changeable URLs.  Functionally, a PURL is a URL, but it is intended to point to an intermediate resolution service.  Its persistence depends upon the updating of a PURL database when the location of the resource changes.  When recorded in field 856, it is intended to allow for persistence so that each record containing the URL need not be updated when the location changes.  Since the PURL is supposed to provide persistent access to the resource, it can be argued that there is no reason to retain a URL that might become invalid.  However, this is an internal decision, and institutions that use PURLs should use subfield $x (Nonpublic note) for the original URL if they wish to retain it.  This is an appropriate subfield, since it may not be desirable to display the URL to the public because it could cause confusion.  The CONSER program has, however, repeated subfield $u to include both the PURL and corresponding URL in the past.

Subfield $y (Link Text):

Subfield $y contains link text which is used for display in place of the URL in subfield $u.  Often URLs are difficult to read and most systems do not display them to the user.  Since subfield $y was not approved until June 2000 (see Proposal 2000-07), there have been various practices in terms of systems using data in the field as link text.  Some systems have used subfields $3 or $z in the past for this purpose.  It is not clear how widespread the use of subfield $y is since its approval.

Subfield $z (Public Note):

Subfield $z may be used for any additional notes about the electronic resource at the specified location.  Examples include subscription information or access restrictions.

Example:  $zInclude desired file format following the hyphen in the filename: EID0ASCII, EID-PDF or EID-PS.

Institutions have used subfield $z in various ways.  Some have created a note for display repeating the URL in subfield $u.  It would be preferable for systems to display subfield $u rather than have those preparing records to include information redundantly.


Topics in this section:

URLs in fields other than field 856

Field 856 in other formats

URLs in fields other than field 856:

Several proposals resulted in the definition of a subfield $u (URI) in other fields.  These fields include:

505  (Formatted Contents Note)

508  (Creation/Production Credits Note)

511  (Participant or Performer Note)

514  (Data Quality Note)

520  (Summary, Etc.)

530  (Additional Physical Form Available Note)

538  (System Details Note)

555  (Cumulative Index/Finding Aids Note)

583  (Action Note)

670  (Source Data Found) in the MARC 21 Format for Authority Data

678  (Biographical or Historical Data) in the MARC 21 Format for Authority Data

As with field 856, subfield $u should be repeated only when both a URL and URN is recorded.

Field 856 in other formats:

Field 856 is also defined in the authority, classification, and community information formats.  It may be used as follows:

Authority format:  Field 856 was defined in June 1998.  Guidelines will be needed from policy making bodies to further describe its use, especially in cooperative projects.  The intent of Proposal No. 98-13 (Define Field 856 in the MARC 21 Authorities Format) was to provide electronic access to Web sites for organizations and other supplementary information within an authority record.

Example:  856 4#$3image$u

Classification format:  Field 856 provides a link from a MARC classification record to a related electronic resource.  This allows for accessing visual aids from an online database of MARC classification records.

Example:  856 7#$u$yMap of West south central states

Community Information format:  Field 856 provides a link from a MARC community information record to community information available on the Web, e.g., Web pages for organizations, events, services, etc.

Example:  856 40$u$ySouthwest Chamber Music in Concert


Field 856 has been used at the Library of Congress as follows:

Records for resources that have been digitized (or otherwise made available electronically) as part of the National Digital Library Program (American Memory) may contain field 856.  Generally, the field is added to the record for the original item, rather than a new record created (unless it consists of components that have been gathered together and only exist as an entity in electronic form).  In some cases, LC has also recorded a handle, which is a URN.  Older records may contain a URN in subfield $g (which is now obsolete).

LC uses local codes in subfield $q to indicate the different categories of a complex object.  This is because digital reproductions created by the Library of Congress are not single files and thus, Internet media types recorded in subfield $q are not applicable.  For example, the reproduction of a book usually combines page images and text marked up in SGML.  See for a complete list of local codes used in subfield $q.

Example:  856 41$dllst$f072$u$qs


The following are major changes made to the August 1999 revision to create these (March 2003 revision) guidelines.

Added a table of contents, along with making other structural changes to enhance the document's readability.

Updated the element list to include the changes made to the repeatability of subfield $u.  Subfield $g was also deleted because it was made obsolete in 2000 (see Proposal 2000-02 for more information).

Added and revised the repeatability guidelines for field 856 and subfield $u.

Updated the "Encoding non-MARC characters" section to include implementation information for the spacing underscore and the spacing tilde.

Added descriptions of subfields $q and $y to the "Specific Data Elements" section.

Expanded the "URLs in fields other than field 856" section to include a complete list of bibliographic and authority fields that include subfield $u.

Expanded and added examples to the "Field 856 in other formats" section.

Expanded the "LC Usage" section to include updated information about how the Library of Congress uses field 856 in various projects.

Deleted the "Attachment B: Subfield Use When Not Using $u (URL)" section.

Updated the examples in the "Examples" section to match current usage of field 856.

FULL RECORD EXAMPLES  (856 Electronic Location and Access):


*   System supplied element

#   Blank

$   Subfield code delimiter


Record #1:  856 link to a subset of the bibliographic item; HTTP URL

Leader  *****nam##*******#a
001  2521854
005  19950215082838.3
008  950215s1994####enk######b#####||||#eng##
040  ##  $aDLC $cDLC $dDLC
050  00  $aHA29$b.A5828 1993
082  00  $a300/.1/5195 $220
245  00  $aAnalyzing qualitative data /$cedited by Alan Bryman and Robert G. Burgess.
260  ##  $aLondon ;$aNew York :$bRoutledge,$c1994.
300  ##  $axii, 232 p. :$bill. ;$c24 cm.
504  ##  $aIncludes bibliographical references and index.
020  ##  $a0415060621
020  ##  $a041506063X (pbk.)
650  #0  $aSocial sciences $xStatistical methods.
650  #0  $aSocial sciences $xResearch $xMethodology.
700  10  $aBryman, Alan.
700  10  $aBurgess, Robert G.
856  4#  $3Table of contents $u


Record #2:  856 link to item itself; HTTP URL

Leader  *****cem##*******#a
001  12934340
005  20021112155042.0
007  cr |||||||||||
008  020918m19999999dcu#a#####|#####|###eng##
010  ##  $a 2002627178
034  0#  $aa
040  ##  $aDLC$cDLC$dDLC
072  #7  $aA25$2lcg
110  2#  $aLibrary of Congress.$bGeography and Map Division.
245  10  $aAmerican Memory map collections: 1500-2002$h[electronic resource].
246  30  $aMap collections: 1500-2002
246  1#  $iTitle from HTML header:$aMap collections home page
255  ##  $aScale not given.
256  ##  $aElectronic data and program.
260  ##  $a[Washington, D.C.] :$bLibrary of Congress,$c[1999-
538  ##  $aMode of access: World Wide Web.
500  ##  $aTitle from home page (viewed 9-18-02).
500  ##  $aPage last updated June 21, 2002.
520  ##  $aThe Geography and Map Division of the Library of Congress offers access to its online map collection for the years 1500-2002. The collection is organized according to seven major categories. Information about the date of publication, subject, medium, call number, and location of each map is provided.
505  0#  $aCities and towns -- Conservation and environment -- Discovery and exploration -- Cultural landscapes -- Military battles and campaigns -- Transportation and communication -- General maps.
651  #0  $aUnited States$vMaps.
650  #0  $aWorld maps.
650  #0  $aMap collections.
610  20  $aLibrary of Congress.$bGeography and Map Division$vMaps.
653  ##  $aInternet resource--Maps
710  2#  $aLibrary of Congress.$bNational Digital Library Program.
856  40  $u


Record #3:  856 with Second Indicator Value 2 for Related electronic resource

This record describes the original manuscript collection; 856 field describes the finding aid for the electronic version of that original.

Leader  *****npc##*******#e
001  mm78052522
008  780918||||||||||||#################eng##
010  ##  $amm 78052522 $bms 69002041
040  ##  $aDLC$cDLC
072  #7  $aL$2lcmd
100  #1  $aJackson, Shirley,$d1919-1965.
245  00  $kPapers,$f1932-1970$g(bulk 1932-1965)
300  ##  $a7,400$fitems.
300  ##  $a51$fcontainers.
300  ##  $a20.4$flinear feet.
520  #8  $aCorrespondence; diaries; journals; mss., typescripts, and galleys of articles, books, and short stories; college notebooks; watercolors; pencil and ink drawings; and other papers pertaining primarily to Jackson's writings. Includes mss., notes, and outlines relating chiefly to the development of Jackson's short stories through which she conveyed her perception of psychological horror lying just beneath the surface of modern life, as well as to her supernatural tales and to her humorous stories of contemporary domestic life. Correspondents include Jackson's husband, Stanley Edgar Hyman, her parents, Leslie H. and Geraldine B. Jackson, Walter Bernstein, Jean Brockway, Elizabeth Batterham ("Libby") Burke, John Ciardi, Pascal Covici, Carol Black Livaudais, June Mirken Mintz, Frank Orenstein, Louis L. Scher, Mary Shaw, Robert M. Strauss, Louis Untermeyer, Jay Williams, the publishing firm of Farrar, Straus and Young, and Jackson's literary agents Brandt & Brandt and the Music Corporation of America.
541  ##  $cGift,$aStanley Edgar Hyman,$d1967.
541  ##  $cTransfer,$aStanley Edgar Hyman papers,$bLibrary of Congress Manuscript Division,$d1979.
541  ##  $cGift,$aVirginia M. Olsen,$d1991.
544  ##  $3Audiotape$etransferred to$aLibrary of Congress Motion Picture, Broadcasting, and Recorded Sound Division.
544  ##  $3Selected artifacts$etransferred to$aSmithsonian Institution.
545  ##  $aAuthor.
555  8#  $aFinding aid available in the Library and on Internet.
600  10  $aBernstein, Walter.
600  10  $aBrockway, Jean.
600  10  $aBurke, Elizabeth Batterham.
600  10  $aCiardi, John,$d1916-
600  10  $aCovici, Pascal,$d1930-
600  10  $aHyman, Stanley Edgar,$d1919-1970.
600  10  $aJackson, Geraldine B.
600  10  $aJackson, Leslie H.
600  10  $aLivaudais, Carol Black.
600  10  $aMintz, June Mirken.
600  10  $aOrenstein, Frank.
600  10  $aScher, Louis L.
600  10  $aShaw, Mary.
600  10  $aStrauss, Robert M.
600  10  $aUntermeyer, Louis,$d1885-1977.
600  10  $aWilliams, Jay,$d1914-
610  20  $aBrandt & Brandt.
610  20  $aFarrar, Straus and Young.
610  20  $aMusic Corporation of America.
650  #0  $aAmerican fiction.
650  #0  $aHorror tales, American.
650  #0  $aHumorous stories, American.
650  #0  $aShort stories, American.
650  #0  $aSupernatural in literature.
656  #7  $aAuthors.$2itoamc
852  ##  $aLibrary of Congress$bManuscript Division$eWashington, D.C.
856  42  $3Finding aid$u


NOTE:  Information for this page is taken from the March 2003 revision of "Guidelines for the Use of Field 856" by Network Development and MARC Standards Office, Library of Congress, located online at:

See also:

856  Electronic Location and Access