Code 608 - Form, Genre or Physical Characteristics Headings (R)Indicators: blankSubfield Codes $a Entry Element (Not repeatable) $x Topical Subdivision (Repeatable) $y Geographical Subdivision (Repeatable) $z Chronological Subdivision (Repeatable) $2 System Code (Not repeatable) $3 Authority Record Number (Not repeatable) $5 Institution to which the Field Applies (Not repeatable)