Compression and Expansion Requirements in 853-855 Fields:  (Input Conventions)

The following conditions must be present in a holdings statement for machine compression or expansion (itemization) to be possible:

Leader/17 Encoding level:

Compression only can be applied to Holdings level 4 detailed holdings statements (Leader/17, code 4) and Holdings level 4 detailed holdings statements with piece designation (Leader/17, code 5).

Expansion can be applied to both types of detailed holdings statements (Leader/17, code 4 or 5) and to Holdings level 3 summary holdings statements (Leader/17, code 3).

Correlation of the 853/854 caption and the 863/864 enumeration level subfields:

Compression and expansion require that the caption subfields ($a-$m) for each of the applicable levels of enumeration and chronology subfields ($a-$m) must be present in the 853/854 Captions and Pattern field that is linked to the 863/864 Enumeration and Chronology field.

Publication pattern subfields $u-$y:

No publication pattern subfields in field 853 or 854 are required for either compression or expansion when the enumeration and chronology in field 863 or 864 consist only of the highest level of enumeration (subfields $a, $g, $i, $m).  When subsequent levels are present, the compression or expansion capability requires pertinent publication pattern information in the following subfields:

$u   Bibliographic units per next higher level

$v   Numbering continuity

$w  Frequency

$x   Calendar change

$y   Regularity pattern

Compression of the contents of subfields $a-$m in field 863 or 864 requires information in subfields $u and $v.  Subfield $u may not contain the code var (varies) or und (undetermined).

Expansion of the contents of subfield $a-$m in field 863 or 864 requires information in subfields $u, $v, and $w and may also require information in subfields $x and $y.

To return:

Use the key.