Code 720 - Linking Heading, Family name
Repeatable for alternative script forms. Indicators not defined
Subfields: a - Entry element (NR) f - Dates (NR) 4 - Relator code (R) x - Topical subdivision (R) y - Geographical subdivision (R) z - Chronological subdivision (R)
Control subfields:
2 - Subject system code (NR) 3 - Record number (NR) 7 - Script (NR) 8 - Language of cataloging (NR)