Library of Congress >> MARC >> Bibliographic >> 5XX  >> 506

506 - Restrictions on Access Note (R)

MARC 21 Bibliographic - full
May 2019

First Indicator Second Indicator
# - No information provided
0 - No restrictions
1 - Restrictions apply

# - Undefined

Subfield Codes
  • $a - Terms governing access (NR)
  • $b - Jurisdiction (R)
  • $c - Physical access provisions (R)
  • $d - Authorized users (R)
  • $e - Authorization (R)
  • $f - Standardized terminology for access restriction (R)
  • $g - Availability date (R)
  • $q - Supplying agency (NR)
  • $u - Uniform Resource Identifier (R)
  • $2 - Source of term (NR)
  • $3 - Materials specified (NR)
  • $5 - Institution to which field applies (NR)
  • $6 - Linkage (NR)
  • $8 - Field link and sequence number (R)


Information about restrictions imposed on access to the described materials.

For published works, this field contains information on limited distribution. For continuing resources, the restrictions must apply to all issues.

If a note merely indicates the intended audience of a publication and does not imply restrictions on access, it is recorded in field 521 (Target Audience Note.) Terms governing the use of materials after access has been allowed are recorded in field 540 (Terms Governing Use and Reproduction).



First Indicator - Restriction

Whether the note states that materials are restricted or unrestricted.

# - No information provided
0 - No restrictions

Field affirms an absence of access restrictions, e.g., open access.

506 0#$aAccess copy available to the general public.$fUnrestricted$2star$5MH
1 - Restrictions apply

Field defines access restrictions to some or all of the material described, e.g., restricted or closed access.

506 1#$aAvailable to subscribing member institutions only.
[An electronic journal that is restricted.]

Second Indicator - Undefined

Contains a blank (#).


$a - Terms governing access

Legal, physical, or procedural restrictions imposed on individuals wishing to see the described materials.

506 ##$aClassified.
506 ##$aFor official use only.
506 ##$aNot available for distribution in the United States.
506 1#$aFor use of the officials of the U.S. and Venezuela Governments only. Any exception will require prior approval of the Venezuelan Government.
506 ##$aConfidential.
506 ##$aNot available for commercial use, sale, or reproduction.
506 1#$aFor restricted circulation--not for publication.
506 ##$aPrior to 1981, distribution was limited to federal judicial personnel.

$b - Jurisdiction

Name of a person, an institution, or a position or function within the institution, by whom or which the terms governing access are imposed and/or enforced, and to whom the restriction may be appealed.

506 1#$3Office files of Under Secretary$aNo one may examine these records or obtain information from them or copies of them except by written permission;$bSecretary of the Treasury or his duly authorized representative;$cKept in remote storage; access requires 24 hours advance notice.

$c - Physical access provisions

Arrangements required for physical access.

Such arrangements may change from time to time.

506 1#$aRestricted: Material extremely fragile;$cAccess by appointment only.
506 ##$aRestricted access;$cWritten permission required;$bDonor.

$d - Authorized users

Class of users or specific individuals (by name or title) to whom the restrictions in subfield $a do not apply.

506 ##$aClosed for 30 years;$dFederal government employees with a need to know.
506 1#$aRestricted: cannot be viewed until 2010;$dMembers of donor's family.

$e - Authorization

Source of authority for the restriction.

506 ##$aClassified under national security provisions;$bDepartment of Defense;$eTitle 50, chapter 401, U.S.C.

$f - Standardized terminology for access restriction

Data taken from a standardized list of terms indicating the level or type of restriction.

506 0#$aAccess copy available to the general public.$fUnrestricted$2star$5MH
506 ##$fUnrestricted online access$2star
506 ##$3Use copy$aAccess available to account holders only.$fOnline access with authorization$2star
506 ##$3Use copy$aIn copyright material. Searches will return text snippets only.$fPreview only$2star
506 ##$aClosed until January 1, 2068.$fNo online access$2star
506 ##$3Master copy$fNo online access$2star

$g - Availability date

Date when the resource changes its access status, e.g., when it becomes freely available. Preferred structure for the date is according to Date and Time (ISO 8601): yyyymmdd.

506 0#$aOpen access$g20190207

$q - Supplying agency

A MARC Organization Code, ISIL, or textual name of the organization or project responsible for the data in the field.

$u - Uniform Resource Identifier

Uniform Resource Identifier (URI), for example a URL or URN, which provides electronic access data in a standard syntax. The data that is accessed by the URI contains additional information about access restrictions.

506 ##$aSome restrictions apply. Consult restricted access file for restriction details:$u[URI]

$2 - Source of term

MARC code that identifies the source of the term used to record the restriction in subfield $f. If terms from different sources are needed, separate fields should be used. Code from: Access Restriction Term Source Codes.

506 1#$aAccess restricted to users with a valid Harvard ID.$fLicense$2star$5MH

$3 - Materials specified

Part of the described material to which the field applies.

506 ##$3All materials except videocassettes$aRestricted.

$5 - Institution to which field applies

See description of this subfield in Appendix A: Control Subfields.

$6 - Linkage

See description of this subfield in Appendix A: Control Subfields.

$8 - Field link and sequence number

See description of this subfield in Appendix A: Control Subfields.


Punctuation - Field 506 ends with a period unless another mark of punctuation is present. If the final subfield is subfield $5, the mark of punctuation precedes that subfield.


Indicator 1 - Restriction [NEW, 2006]
$f - Standardized terminology for access restriction [NEW, 2006]
$g - Availability date [NEW, 2019]
$q - Supplying agency [NEW, 2019]
$u - Uniform Resource Identifier [NEW, 2002]
$2 - Source of term [NEW, 2006]

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