863-865 $8 - Link and sequence number:

Subfield $8 contains data that links an Enumeration and Chronology field to its related 853-855 Captions and Pattern or 876-878 Item Information field . The subfield is structured as follows:

<linking number>.<sequence number>

The linking number is a variable-length whole number. The linking number that is used in an Enumeration and Chronology field must be the same linking number that is used in the 853-855 field that contains the captions and publication pattern for the 863-865 field. Example 1

A variable-length sequence number is added to the linking number to control the display and processing sequence of multiple occurrences of an 863-865 field that contains identical linking numbers. A sequence number is separated from a linking number by a decimal point. Subfield $8 is always the first subfield in the field. Example 2

Subfield $8 (Link and sequence number) is always the first subfield in the field.