(RFC 2220 published October 1997, subtype last updated October 1997) Media type name: application Media subtype name: marc Required parameters: None Optional parameters: None Encoding considerations: MARC records may contain long lines and/or arbitrary octet values. The base64 content-transfer-encoding is recommended for transmission of MARC over electronic mail. Security Considerations There are no known security risks associated with the use or viewing of MARC data. A MARC record may have security classification associated with the document it describes or metadata in that record. Although this does not present any security risk to the user of MARC data, it may provide an opportunity for a security breach for the source of classified MARC data. Interoperability Considerations MARC is a communication format and is designed for interoperability between different systems that may store data in local formats internally. Published Specification "USMARC Format for Bibliographic Data"; "USMARC Format for Authority Data"; "USMARC Format for Holdings Data"; "USMARC Format for Classification Data"; "USMARC Format for Community Information". Additional information: File extension: .mrc OID: 1.2.840.10003.5.10 Person & email address to contact for further information: Network Development & MARC Standards Office 101 Independence Ave. SE Library of Congress Washington, DC 20540-4102 U.S.A.