Field 580 is used to express complex relationships that cannot be accurately generated by using the display constants associated with the linking entry fields (765-787). It is also used for regular-print reprints to provide details of the original. Notes for relationships involving the 776 field (Additional physical form entry) are recorded in field 530. (CEG5xxp54) The most common examples are when a chronological relationship involves more than one title, requiring multiple linking entry fields, such as (Merged with:... to form: . . ).
When optional date information is provided with a continued by or "absorbed by" note.
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