Indicators
Both undefined; each contains a blank (^)
Subfield Codes
$a Chronological term (NR)
$i Reference instruction phrase (R)
$v Form subdivision (R)
$w Control subfield (NR)
/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
t Immediate parent body
| fill character
/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
| fill character
/2 Earlier form of heading
a Pre-AACR 2 form of heading (national name authority file)
e Earlier established form of heading (national authority file)
o Earlier established form of heading (other authority file)
n Not applicable
| fill character
/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
$x General subdivision (R)
$y Chronological subdivision (R)
$z Geographic subdivision (R)
$5 Institution to which field applies (R)
$6 Linkage (NR)
$8 Field link and sequence number (R)