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506  Restrictions on Access Note (R)


Input Standards

1st Indicator  Restriction
blank character No information provided
No restrictions
1 Restrictions apply
2nd Indicator  Undefined
blank character Undefined
Subfields (R=Repeatable  NR=Nonrepeatable) Input Standards 
‡a Terms governing access (NR) Required if applicable/Required if applicable
‡b Jurisdiction (R) Required if applicable/Required if applicable
‡c Physical access provisions (R) Required if applicable/Required if applicable
‡d Authorized users (R) Required if applicable/Required if applicable
‡e Authorization (R) Required if applicable/Required if applicable
‡f Standardized terminology for access restriction (R) Optional/Optional
‡u Uniform Resource Identifier (R) Optional/Optional
‡2 Source of term (NR) Required if applicable/Required if applicable
‡3 Materials specified (NR) Optional/Optional
‡5 Institution to which field applies (NR) Required if applicable/Optional


A note about the restrictions imposed on access to the described materials. For published works, this field contains information on limited distribution.

Use field 521 if a note merely indicates the intended audience of a publication and does not imply restricted access. Use field 540 for terms governing the use of materials after access has been granted. Use field 590 if the note indicates local limited use (e.g., kept in a locked closet).


Note: For continuing resources, the restrictions must apply to all issues.

1st Indicator

blank character No information provided. No information provided about whether the note states that materials are restricted or unrestricted.
No restrictions. No restrictions on materials.
1 Restrictions apply. Restrictions apply to some or all of the material.

2nd Indicator

Undefined. The 2nd indicator position is undefined and contains a blank ( blank character ).
blank character Undefined 


‡a Terms governing access   Legal, physical or procedural restrictions imposed on individuals wishing to see the described materials.
506 1   Available to subscribing member institutions only.
[A note for an electronic journal that is restricted] 
506 1   Classified.
506 1   Confidential.
506 1   Not available for commercial use, sale, or reproduction.
506 1   Open to investigators with permission of the Clark family.
506 1   Prior to 1981, distribution was limited to federal judicial personnel.
506 1   Some of the personal correspondence is restricted until Oct. 1, 1983.
‡b Jurisdiction   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 1   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 infromation 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   Any arrangements required for physical access that may change from time to time.
506 1   Restricted: Material extremely fragile; ‡c Access by appointment only.
‡d Authorized users   The class of users or specific individuals (by name or title) for whom the restrictions in subfield ‡a do not apply.
506 1   Closed for 30 years; ‡d Federal government employees with a need to know.
‡e Authorization   The source of the authority for the restriction.
506 1   Classified under national security provisions; ‡b Department of Defense; ‡e Title 50, chapter 401, U.S.C.
‡f Standardized terminology for access restriction   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 1   Closed until January 1, 2068. ‡f No online access. ‡2 star
‡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).
506 1   Some restrictions apply. Consult restricted access file for restriction details: ‡u [URI]

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 hexidecimal 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 line 1   _ %5F
Spacing grave/grave accent ` %60
Spacing tilde/tilde ~ %7E
Enter as hex value only vertical bar n/a %7C

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

‡2 Source of term   The MARC code identifying the source of the term used to record the restriction in subfield ‡f. Use a separate subfield for each source. See Access Restriction Term Source Codes (
506 1   ‡3 Use copy ‡a In copyright material. Searches will return text snippets only. ‡f Preview only. ‡2 star
‡3 Materials specified   The part of the described materials 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   A code of the institution or organization that holds the copy to which the field applies. Use for notes that do not apply to the universal description of the item. See MARC Code List for Organizations ( or Symbols and Interlibrary Loan Policies in Canada (


Field 506 prints as a note. Subfields ‡u and ‡5 do not print. See "5xx Introduction" for more information.

Last revised: February 3, 2014