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506 Restrictions on Access Note (R)

Find the field definition and scope, indicators, subfield codes, and guidelines for applying content designations for field 506.

Indicators and subfield codes

First Indicator


blank         No information provided

0        No restrictions

1         Restrictions apply

Second Indicator


blank         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 restrictions (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)

‡8       Field link and sequence number (R)


Field definition and scope

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.

Guidelines for applying content designations


First Indicator - Restriction

Indicates whether materials are restricted or unrestricted.

blank - No information provided

Value blank indicates that no information is provided about whether the note states that materials are restricted or unrestricted.

0 - No restrictions

No restrictions on access to materials.

1 - Restrictions apply

Access restrictions on some or all of the material.

Second Indicator - Undefined

The second indicator is undefined and contains a blank (blank).

blank - Undefined


‡a - Terms governing access

Subfield ‡a defines legal, physical, or procedural restrictions imposed on individuals wishing to see the described materials.

506  1    Classified.

506  0   Available to subscribing member institutions only.

506  1    Confidential.

‡b - Jurisdiction

Subfield ‡b contains the name of a person, an institution or a function or position 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        Restricted access; ‡c Written permission required; ‡b Donor

506  1    ‡3 Office files of Under Secretary ‡a No one may examine these records or obtain information from them or copies of them except by written
               permission; ‡b Secretary of the Treasury or his duly authorized representative; ‡c Kept in remote storage; access requires 24 hours advance notice.

‡c - Physical access provisions

Subfield ‡c describes any arrangements required for physical access that may change from time to time.

506  0   Restricted: Material extremely fragile; ‡c Access by appointment only.

‡d - Authorized users

Subfield ‡d defines the class of users or specific individuals (by name or title) for whom the restrictions in subfield ‡ a do not apply.

506        Closed for 30 years; ‡d Federal government employees with a need to know.

‡e - Authorization

Subfield ‡e identifies the source of the authority for the restriction.

506  0   Classified under national security provisions; ‡b Department of Defense; ‡e Title 50, chapter 401, U.S.C.

‡f - Standardized terminology for access restriction

Subfield ‡f contains data taken from a standardized list indicating the level or type of restriction. You may use terms of your choice or those from the Standardized Terminology for Access Restriction from the DLF/OCLC Registry of Digital Masters Working Group.

506        Closed until January 1, 2068. ‡f No online access ‡2 star

‡g - Availability data

Subfield ‡g contains the date when the resource changes its access status (e.g., when it becomes freely available). Preferred structure for the date is according to the format yyyymmdd in accordance with ISO 8601, Representation of Dates and Times. The mm and dd positions contain zeroes when the data is unknown.

506    0         Open access ǂg 20190207

‡q - Supplying agency

Subfield ‡q contains a MARC Organization Code, International Standard Identifier for Libraries and Related Organizations (ISIL), or textual name of the organization or project responsible for the data in the field. See MARC Code List for Organizations, which also includes links to Canadian, United Kingdom, and German MARC Organization Code lists, along with the International Standard Identifier for Libraries and Related Organizations (ISIL).

506              This collection is open for research ǂq InMuB

‡u - Uniform Resource Identifier

The Uniform Resource Identifier (URI), for example a URL or URN, provides electronic access data in a standard syntax. The data that is accessed by the URI contains additional information about access restrictions. Repeat subfield if digital object has multiple identifiers (URIs).

Substituting hexadecimal notation for diacritics and special characters in Uniform Resource Identifiers. When recording a URI in subfield ‡u, you may enter most of the spacing characters listed below as either characters or their hexadecimal equivalents. Consult the table below.

 Note: Do not confuse the spacing characters listed below with their long-valid non-spacing counterparts. Use of the spacing characters will be limited almost exclusively to URLs.

Entry method Name Character Alternative entry (hex value)
Enter as character or hex value Spacing circumflex/circumflex accent ^ %5E
Spacing underscore/low line1 _ %5F
Spacing grave/grave accent ` %60
Spacing tilde/tilde ~ %7E
Enter as hex value only Vertical bar n/a %7C

1Because the Spacing Underscore may cause problems with MARC output, users may prefer to continue entering it with the hexadecimal value %5F.

506  1   Some restrictions apply. Consult restricted access file for restriction details: ‡u <URI>

‡2 - Source of term

Subfield ‡2 contains a MARC code identifying the source of the term used to record the restriction in subfield ‡f. Use a separate subfield for each source. The source of the MARC code is Access Restriction Term Source Codes that is maintained by the Library of Congress.

506  1   ‡3 Use copy ‡a In copyright material. Searches will return text snippets only. ‡f Preview only ‡2 star

‡3 - Materials specified

Subfield ‡3 indicates the part of the described material to which the field applies.

506  1   ‡3 Office files of Under-Secretary ‡a No one may examine these records or obtain information from them or copies of them except by written
              permission; ‡b Secretary of the Treasury or his duly authorized representative; ‡c Kept in remote storage; Access requires 24 hours advance notice.

‡5 - Institution to which field applies

Subfield ‡5 contains the MARC code of the institution or organization that holds the copy to which the data in the field applies. It is used for institution-specific information that may or may not apply to the universal use of the holdings record. See MARC Code List for Organizations, which also includes links to Canadian, United Kingdom, and German MARC Organization Code lists.

506  1   Access restricted to users with a valid Harvard ID ‡f License ‡2 star ‡5 MH

‡8 - Field link and sequence number

Subfield ‡8 contains data that identifies linked fields and may also propose a sequence for the linked fields. Subfield ‡8 may be repeated to link a field to more than one other group of fields.

The structure and syntax for the field link and sequence number subfield is: ‡8<linking number>.<sequence number>\<field link type>

The linking number is the first data element in the subfield and required if the subfield is used. It is a variable-length whole number that occurs in subfield ‡8 in all fields that are to be linked. Fields with the same linking number are considered linked.& A linking number of "0" (zero) is not used in this field.

The sequence number is separated from the linking number by a period "." and may be optional. It is a variable-length whole number that may be used to indicate the relative order for display of the linked fields (lower sequence numbers displaying before higher ones).

The field link type is separated from preceding data by a reverse slash "\". It is a code indicating the reason for the link and it follows the link number or sequence number if present. The following one-character field link type code has been defined for use in subfield 8 in OCLC local holdings records: a - Action

Code a is used in a record to link one or more fields with another field to which the processing or reference actions relate. This code is typically used only when there is more than one 5XX that relates to another 5XX field.

541          ‡8 1.1\a ‡3 Public School and College Authority and Trade School and Junior College Authority project files ‡a Finance Dept ‡c
                Transferred ‡u

583          ‡8 1.2\a ‡a Appraised ‡c 198712- ‡l tjb/prr

583          ‡8 1.3\a ‡a Scheduled ‡c 19880127 ‡k mc/dmj

583          ‡8 1.4\a ‡a Arranged ‡c 19900619 ‡k mc/dmj

583          ‡8 1.2\a ‡a Processed level 2 ‡b 90.160 ‡c 19901218 ‡k kmc/dmj