Descriptions for data elements which are an integral part of the MARC 21 Format for Bibliographic Data and data elements which may appear either in bibliographic records or in separate MARC holdings records.
Field 850 is a bibliographic record field that contains minimal holdings location data. Field 852 contains more extensive location data. Field 856 covers information about the location of electronic resources. These fields are described fully in this format. Fields 841-845, 853-855, and 863-878 are only listed here.
Full descriptions for them appear in the MARC 21 Format for Holdings Data. The holdings format should be consulted for field descriptions and information concerning the inclusion of fields 841-845, 853-855, and 863-878 in bibliographic records.
Fields 870, 871, 872, and 873 were defined for the serials specifications in 1979. The subfield codes were the same as the corresponding heading field, with the addition of subfield $j (Tag and sequence number of the field for which the 87X field is a variant). The first indicator in each field was the same as in the corresponding 1XX, 4XX, 6XX, 7XX, or 8XX heading field. The second indicator specified the form of heading: