Subfield $8 contains data that identifies linked fields and may also propose a sequence for the linked fields.  Subfield $8 may be repeated to link a field to more than one other group of fields.  The structure and syntax for the field link and sequence number subfield is:

$8[linking number].[sequence number]\[field link type]

Please note that subfield $8 is defined differently in field 852 (Location) where it is used to sequence related holdings records.  Please see the description of field 852, subfield $8 in the MARC 21 Format for Holdings Data for more information.

The linking number is the first data element in the subfield and required if the subfield is used.  It is a variable-length whole number that occurs in subfield $8 in all fields that are to be linked.  Fields with the same linking number are considered linked.

The sequence number is separated from the linking number by a period ( . ) and is optional.  It is a variable-length whole number that may be used to indicate the relative order for display of the linked fields (lower sequence numbers displaying before higher ones).  If it is used it must occur in $8 subfields containing the same linking number.

The field link type is separated from preceding data by a reverse slash ( \ ).  It is a code indicating the reason for the link and it follows the link number, or sequence number if present.  Field link type is required except when subfield $8 is used to link and sequence 85X-87X holdings fields.  The following one-character field link type codes have been defined in MARC for use in subfield $8:

a - Action

Code a is used in a record to link one or more fields with another field to which the processing or reference actions relate.  This code is typically used only when there is more than one 5XX that relate to another 5XX field.

541  ##  $81.1\a$3Public School and College Authority and Trade School and Junior College Authority project files$aFinance Dept.$cTransferred

583  ##  $81.2\a$aappraised$c198712-$ktjb/prr

583  ##  $81.3\a$ascheduled$c19880127$ksrc/prr

583  ##  $81.4\a$aarranged$c19900619$kmc/dmj

583  ##  $81.5\a$aprocessed level 2$b90.160$c19901218$kmc/dmj

c - Constituent item

Code c is used in a record for a collection, or a single item consisting of identifiable constituent units, to link the fields relating to the constituent units.  All other non-linked data elements in the record pertain to the collection or item as a whole.

Example:

245  10  $aBrevard Music Center$nProgram #24$h[sound recording].

505  0#  $aFrom my window / Siegmesiter (world premiere) - Don Giovanni. Il mio tesorof [i.e. tesoro] / Mozart - Martha. M'appari / Flotow - Turandot. Nessun dorma / Puccini - Pines of Rome / Respighi.

650  #0  $81\c$aSuites (Orchestra), Arranged.

650  #0  $82\c$83\c$84\c$aOperas$xExcerpts.

650  $0  $85\c$aSymphonic poems.

700  1#  $82\c$84\c$aDi Giuseppe, Enrico,$d1938-$4prf

700  12  $81\c$aSiegmeister, Elie,$d1909-$tFrom my window;$oarr.

700  12  $82\c$aMozart, Wolfgang Amadeus,$d1756-1791.$tDon Giovanni.$pMio tesoro.

700  12  $83\c$aFlotow, Friedrich von,$d1812-1883.$tMartha.$pAch! So fromm, ach! so traut.$lItalian

700  12  $84\c$aPuccini, Giacomo,$d1858-1924.$tTurandot.$pNessun dorma.

700  12  $85\c$aRespighi, Ottorino,$d1879-1936.$tPini di Roma.

p - Metadata provenance

Code p is used in a record to link a field with another field containing information about provenance of the metadata recorded in the linked field.

Example:

082  04  $81\p$a004$222/ger$qDE-101

883  0#  $81\p$aparallelrecordcopy$d20120101$x20141231$qNO-OsNB

r - Reproduction

Code r is used in a record for a reproduction to identify fields linked because they contain information concerning only the reproduction.  Other descriptive information in the record pertains to the original [with the exception of field 007 (Physical Description Fixed Field), 008 (Fixed-Length Data Elements:  Books, Music, Serials, or Mixed Material positions 23 (Form of item)), field 245 subfield $h (Title Statement / Medium), and field 533 (Reproduction Note)].

Example:

007/00   h   <microform>

008/23   a   <Microfilm>

245  04  $aThe New-York mirror, and ladies' literary gazette$h[microform]

533  ##  $aMicrofilm$bAnn Arbor, Mich. :$cUniversity Microfilms,$d1950.$e3 microfilm reels ; 35 mm.$f(American periodical series, 1800-1850 : 164-165, 785)

830  #0  $84\r$aAmerican periodical series, 1800-1850;$v164-165, 785.

u - General linking, type unspecified

Code u is used in cases when a specific link type is not appropriate.  Code u may serve as a default value when there is no information about the reason for the link available.

Example:

082  04  $81\u$a779.994346228092$qDE-101$222/ger

085  ##  $81\u$b779

085  ##  $81\u$s704.949

085  ##  $81\u$s943

085  ##  $81\u$z1$s092

085  ##  $81\u$z2$s4346228

245  10  $a-Der- Bodensee$b= Lake Constance$cHolger Spierling ; mit Texten von Iris Lemanczyk ; Übersetzung: Global-Text, Heidelberg, Timothy Gilfoid

x - General sequencing

Code x is used in a record to make a link between fields to show a sequence between them.  The sequence could be one that orders the pieces of a long field that has been broken up, indicates the relative importance of fields within the sequence, or is used for some other sequencing purpose.  Use of the sequence number in $8 is required when this code is used.

Example:

505  00  $81.1\x$tThree articles reviewing Hoeffding's work.$tWassily Hoeffding's Work in the Sixties /$rKobus Oosterhoff and Willem van Zwet.$tThe Impact of Wassily Hoeffding's Work on Sequential Analysis /$rGordon Simons.$tThe Impact of Wassily Hoeffding's Research on Nonparametrics /$rPranab Kumar Sen ...

505  80  $81.2\x$tThe role of assumptions in statistical decisions.$tDistinguishability of sets of distributions. (The case of independent and identically distributed random variables) /$rWassily Hoeffding and J. Wolfowitz ...

505  80  $81.3\x$tUnbiased range-preserving estimators.$tRange preserving unbiased estimators in the multinomial case.$tAsymptotic normality.$tHajek's projection lemma.

[This example shows a long 505 field broken up into smaller pieces]

To return:

Use the key.

See also:

Appendix A:  Control Subfields