856 Electronic Location and Access

Field definition and scope:

Field 856 contains the information needed to locate and access electronic information. The field may be used in a classification record for a resource when that resource 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 the classification record or a related electronic resource. This field may also be used to link to an electronic resource intended to supplement the classification scheme, e.g., an image of a map.

Field 856 is repeated when the location elements vary (the URL in subfields $a and $c, when used). It is also repeated when more than one access method is used, mirror sites are recorded, different formats/resolutions with different URLs are indicated, and related items are recorded.

Field 856 is repeatable.

See the Guidelines for the Use of Field 856 for a more thorough discussion on the use of field 856. It is located online at: www.loc.gov/marc/856guide.html.

Guidelines for applying content designators:

For indicator and subfield code definitions and examples, and designator repeatability, see table below:

Position	Description	Repeatability
Field 856	Electronic Location and Access	R
Indicator:
First	Access method
#	No information provided
0	Email
1	FTP
2	Remote login (Telnet)
3	Dial-up
4	HTTP
7	Method specified in subfield $2

Second	Relationship
#	No information provided
0	Resource
1	Version of resource
2	Related resource
8	No display constant generated

Subfield code:
$a	Host name	R
$c	Compression information	R
$d	Path	R
$f	Electronic name	R
$m	Contact for access assistance	R
$o	Operating system	NR
$p	Port	NR
$q	Electronic format type	NR
$s	File size	R
$u	Uniform Resource Identifier	R
$v	Hours access method available	R
$w	Record control number	R
$x	Nonpublic note	R
$y	Link text	R
$z	Public note	R
$2	Access method	NR
$3	Materials specified	NR
$6	Linkage	NR
$7	Access status	NR
$8	Field link and sequence number	NR

See: Example for this field.

Input conventions:

Spacing underscore and tilde in URLs

Content designator history:

Subfield $b Access number [obsolete, 2020]

Subfield $g - Uniform Resource Name [obsolete, 2000]: Because subfield $g (Electronic name - End of range) was rarely if ever used, it was redefined as Uniform Resource Name in 1997. It was subsequently made obsolete in favor of recording the URN in subfield $u.

Subfield $h Processor of request [obsolete, 2020]

Subfield $i Instruction [obsolete, 2020]

Subfield $j Bits per second [obsolete, 2020]

Subfield $k Password [obsolete, 2020]

Subfield $l Logon [obsolete, 2020]

Subfield $n Name of location of host [obsolete, 2020]

Subfield $q File transfer mode [redefined, 1997]: Subfield $q was defined to contain an indication of whether the file was transferred as binary or ASCII. It was redefined to contain type of electronic format.

Subfield $r Settings [obsolete, 2020]

Subfield $t Terminal emulation [obsolete, 2020]

Subfield $u - Uniform Resource Identifier [renamed, 2000]: Prior to 1999, subfield $u was defined as Uniform Resource Locator and was repeatable. It was changed to not repeatable because of ambiguity in determining when the subfield could be repeatable. Subfield $u was changed back to repeatable and renamed Uniform Resource Identifier in 2000 to record both URLs and URNs after subfield $g was made obsolete.

Subfield $y - Link text [new, 2000]

Subfield $7 - Access status [new, 2019]