Display constants for field 022:

ISSN [associated with the content of subfield $a ]

ISSN (incorrect) [associated with the content of subfield $y ]

ISSN (canceled) [associated with the content of subfield $z ]

An ISSN usually appears on an item with the prefix ISSN and as two groups of four digits separated by a hyphen. The hyphen separating the two groups of digits is carried in the MARC record. The initialism ISSN and the phrases ISSN (incorrect) and ISSN (canceled) are not carried in the MARC record. They may be system generated as display constants associated with the content of subfields $a, $y, and $z, respectively.

Content designated field:

022 0#$a0018-5817$y0018-5811

Display example:

ISSN 0018-5817 ISSN (incorrect) 0018-5811