Control subfield ‡w elements
Control subfield ‡w in the 4xx and 5xx fields contains 4 bytes (designated as ‡w/0, ‡w/1, etc). It provides information about a specific relationship between a heading (1xx field) and tracing (4xx or 5xx field).
- Use to indicate whether special instructions apply to the display of the heading in the 4xx or 5xx field.
- Use to indicate whether a tracing is restricted to the reference structure of a particular type of authority.
- Each character position has a list of coded values that pertain to it. See the table below.
- The meaning of a value depends on the character position in which it appears.
The code definitions are position-dependent. Coding any character position with a value other than n (not applicable) mandates coding the preceding positions. Succeeding positions need not be coded. If all 4 positions contain n, subfield ‡w does not appear.
Control subfield ‡w character positions in 4xx and 5xx fields
Ind = Indicator | SFC = Subfield code | R = Repeatable | NR = Nonrepeatable |
= Blank
| Byte | Code | Description |
|---|---|---|
| ‡w/0 |
Special Relationship
|
|
| a | Earlier heading | |
| b | Later heading | |
| d | Acronym | |
| f | Musical composition | |
| g | Broader term | |
| h | Narrower term | |
| i | Reference instruction phrase in subfield ‡i | |
| n | Not applicable | |
| r | Relationship designation in subfield ‡i or ‡4 | |
| ‡w/1 |
Tracing Use Restriction
|
|
| a | Name reference structure only | |
| b | Subject reference structure only | |
| c | Series reference structure only | |
| d | Name and subject reference structures | |
| e | Name and series reference structures | |
| f | Subject and series reference structures | |
| g | Name, subject, and series reference structures | |
| n | Not applicable | |
| ‡w/2 |
Earlier Form of Heading
|
|
| a | Pre-AACR2 form of heading (national name authority file) | |
| e | Earlier established form of heading (national authority file) | |
| n |
Not applicable (tracing is not the earlier form of heading)
|
|
| o | Earlier established form of heading (other authority file) | |
| ‡w/3 |
Reference Display
|
|
| a | Reference not displayed | |
| b | Reference not displayed, field 664 used | |
| c | Reference not displayed, field 663 used | |
| d | Reference not displayed, field 665 used | |
| n | Not applicable (reference displayed from tracing | |
Control subfield ‡w in 7xx fields
Control subfield ‡w in the 7xx fields contains one byte (designated as ‡w/0). It controls the generation of a link display from a 700–785 field. Use subfield ‡w to suppress the display. Subfield ‡w has 4 values.
Control subfield ‡w character position in 7xx fields
Ind = Indicator | SFC = Subfield code | R = Repeatable | NR = Nonrepeatable |
= Blank
| Byte | Code | Description |
|---|---|---|
| ‡w/0 |
Link Display
|
|
| a | Link not displayed | |
| b | Link not displayed, field 788 used | |
| c | Link not displayed, non-7xx field used | |
| n | Not applicable |
