453 / 553 Subfield $w/1-g - Number representing broader topic:
Code g indicates that the number in the tracing field represents a broader topic than the number at the preceding level of the caption hierarchy that is contained in field 153 (Classification Number). The code may be used to generate a special reference instruction phrase such as see also under the narrower number: in a cross reference display.
Example:
084 0# $addc$c21 [Dewey Decimal Classification]
153 ## $a621.252$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$kFluid-power technologies$hHydraulic-power technology$hPumps and accumulators$jPumps
553 0# $wjg$a621.69$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jPumps. Pneumatic pumps$thydraulic pumps
084 0# $addc$c21 [Dewey Decimal Classification]
153 ## $a621.64$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jHand pumps
553 0# $wjg$a621.69$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jPumps. Pneumatic pumps$thand pumps
084 0# $addc$c21 [Dewey Decimal Classification]
153 ## $a621.65$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jReciprocating pumps
553 0# $wjg$a621.69$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jPumps. Pneumatic pumps$treciprocating pumps
084 0# $addc$c21 [Dewey Decimal Classification]
153 ## $a621.66$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jRotary pumps
553 0# $wjg$a621.69$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jPumps. Pneumatic pumps$trotary pumps
084 0# $addc$c21 [Dewey Decimal Classification]
153 ## $a621.67$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jCentrifugal pumps
553 0# $wjg$a621.69$hTechnology (Applied sciences)$hEngineering and allied operations$hApplied physics$hBlowers, fans, pumps$kPumps$jPumps. Pneumatic pumps$tcentrifugal pumps
Cross reference display at 621.69:
For hydraulic pumps, see 621.252; for hand pumps, see 621.64; for reciprocating pumps, see 621.65; for rotary pumps, see 621.66; for centrifugal pumps, see 621.67
[In this example, subfield $w/0 controls the display, which is for a see reference.]
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