Step 3.1

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normalization and matching

Normalization of the name headings is different. All information in the personal name heading is considered when determining matches. Only $a of the name heading is removed (i.e., the delimiter and subfield, not the data within $a).

Name headings are defined as bib fields 100 (along with 240/243), 600, 700, and 800. Death date and other information in the bib heading date will always be considered. A bib heading with a death date will not match against an authority heading without one.

Normalization of a name heading is as follows:

Original Bib Heading Authority Record
700 1 $a Pinsent, John, $d 1922- 400 1 $a Pinsent, John, $d 1922-
100 1 $a Pinsent, John, $d 1922-1995

Normalized Bib Heading Normalized Authority
700 1 PINSENT, JOHN $ 1922 400 1 PINSENT, JOHN $ 1922
100 1 PINSENT, JOHN $ 1922 1995

Matched Bib Heading Authority Control No.
700 1 $a Pinsent, John, $d 1922-1995 n 50011026

In this case, the original heading contained a birth date yet lacked a death date. However, when a valid cross-reference exists (e.g., the older form used in this example) the match can then be updated with the death date.

When multiple matches occur on personal name headings, the bib heading will not be replaced with any of the matches. In the case with multiple potential authority matches, the program cannot know which one to take over the others and so the bib heading remains unchanged. The multiple potential authority matches will be reported to the user in Heading Matches Multiple Authority Records (see Step 5.2, R10).

During the final phase of Authority Control, the incorrect form of the heading in the bibliographic record is replaced by the established form of the authority record. The corrected heading contains missing or changed diacritics.

bibliographic text replaced

When a heading matches a 1XX authorized heading or a 4XX unauthorized heading in an authority record, MARS 2.0 processing:

  • Replaces the bibliographic heading text with the text from the 1XX field of the authority record
  • Replaces the second and third characters of the bibliographic tag with the second and third characters of the 1XX authority heading tag, as appropriate (see “6XX Tag Flipping” in Step 3.2 of the Planning Guide)

This replacement process corrects errors in capitalization, punctuation, spacing, subfield coding and some tagging errors. MARS 2.0 ensures that the appropriate ending punctuation is supplied in the bibliographic heading.


Currently if you have a generic name heading (no date or full form of name) in your bib record and a match is found on a See reference 400 of an LC Personal Name authority record, MARS 2.0 will automatically flip the authority heading to reflect the new authority:

 generic bib heading:
 100 10 $a Campbell, John
 finds match to authority below:
 001 n2001026796
 100 10 $a Campbell, John, $d 1826-1910
 400 10 $a Campbell, John
 generic bib heading changes to:
 100 10 $a Campbell, John, $d 1826-1910

Choosing to flip on generic name headings will give you a greater match rate, but it can cause mismatched headings. MARS 2.0 allows for the flip of all name authority headings including the generic name heading if there is a match to a See reference 400 in the LC authority record.


MARS 2.0 Authority Matching software looks at both the authorized (or established) form of a heading in the authority record’s 1XX field and the unauthorized form in the 4XX fields (See From tracings):

 original bib headings:
 650 0 $a Philippine American War, Philippines, 1899-1902.
 651 0 $a Philippines $x History $y Insurrection, 1899-1901.
 651 0 $a United States $x History $y Philippine Insurrection, 1899-1902.

The normalized headings from the bibliographic records are compared to the normalized authorized 1XX and the unauthorized 4XX authority record headings.

 The headings above match headings contained in sh 85100792 - LC subject authority record:
 001 sh 85100792
 151 0 $a Philippines $x History $y Philippine American War, 1899-1902
 450 0 $a Filipino American War, Philippines, 1899-1902
 450 0 $a Philippine American War, Philippines, 1899-1902
 450 0 $a Philippine Insurrection, Philippines, 1899-1902
 451 0 $a Philippines $x History $y Insurrection, 1899-1901
 451 0 $a United States $x History $y Philippine Insurrection, 1899-1902
 The three unauthorized headings in the bibliographic record would all be replaced by the established form of the heading:
 151 0 $a Philippines $x History $y Philippine American War, 1899-1902
 MARS 2.0 then merges or deduplicates the three identical authority headings to form one heading:
 651 0 $a Philippines $x History $y Philippine American War, 1899-1902


Unauthorized headings (See From tracings) are often included only in the authority record for the highest level of a heading. The authority record for Apples, for instance, contains the older form of the heading, Apple. The authority record for the fuller heading, Apples — Marketing, however, does not contain a tracing for Apple — Marketing.

Using all hierarchy levels during Authority Matching, i.e., the highest level Apples plus all fuller forms such as Apples — Marketing and Apples — Washington (State) — Marketing, allows a greater number of heading updates.

Normalized headings are constructed for each level of hierarchy in the heading:

 original bib heading:
 650 0 $a Electronic digital computers $x Programming $v Congresses.
 levels of hierarchy for this heading:
 650 0 $a Electronic digital computers
 650 0 $a Electronic digital computers $x Programming
 650 0 $a Electronic digital computers $x Programming $v Congresses
 partial match to 4XX heading in LC subject sh 85107310:
 150 0 $a Computer programming
 450 0 $a Electronic digital computers $x Programming
 corrected form of heading in bib record (a partial match):
 650 0 $a Computer programming $v Congresses.

constructing multiple levels of hierarchy

When constructing multiple levels of hierarchy for a heading, the shortest form of the heading that is matched against the authority file is referred to as the highest level of the heading:

 full heading:
 700  12 $a Freud, Sigmund, $d 1856-1939. $t Selections. $f 1990
 highest level heading:
 700  12 $a Freud, Sigmund, $d 1856-1939

hierarchy record delivered to marc file

When a hierarchy match is found not only is the authority heading replaced with the appropriate authority record, but the hierarchal version of the authority record is delivered to your MARC authority file allowing appropriate cross references to be connected to your new heading.

subfields representing highest level heading

MARS 2.0 drops the right-most subfield(s) in generating a higher-level heading and it stops (it has reached the highest level heading) when it encounters any subfield code in the following table:

Subfield Codes Indicating Highest Level Heading
100, 400, 600, 700, 800 a b c d q
110, 410, 610, 710, 810 a b
111, 411, 611, 711, 811 a b
130, 430, 630, 730, 830 a d
440 a
650 a c d
651 a
655 a


Name/title headings, which are often coded as a $a / $t combination in either a 7XX or 6XX field, present a unique challenge. LC authority records containing the full name/title headings have been established and would be matched during normal MARS 2.0 authority matching:

 name/title combined headings:
 600  10 $a Twain, Mark, $d 1835-1910. $t Innocents abroad.
 710  1  $a Canada. $t Treaties, etc. $d 1992 Oct. 7.

name/title split and temporary headings

At other times, however, the name/title heading is split between two fields, a 1XX Main Entry and a 240 Uniform Title. In order to correctly process 1XX/240 name/title headings, temporary headings are built whenever a record contains both a 1XX and 240 field:

 bib headings:
 100   0 $a Aristotle.
 240  10 $a Works. $l English. $f 1984
 changes to:
 100   0 $a Aristotle. $t Works

Using normal matching, the 100 field above would match the authority record for Aristotle. There is no authority record, however, for the uniform title found in the 240 field. The two fields (100/240) are combined during the matching process only.

 The temporary MARS 2.0 autohrity heading would then match the correct LC authority record n  8242241:
 100   0 $a Aristotle. $t Works. $l English. $f 1984
 400   0 $a Aristotle. $t Complete works of Aristotle. $f 1984

name/title tracing

Inclusion of LC authority records in a library’s record distribution is an important MARS 2.0 service. Most local systems use the 400 See From tracing in the above authority record to guide patrons from the unauthorized to the authorized heading using a display similar to the following:

 Aristotle - Complete works of Aristotle - 1984
   See Aristotle - Works - English - 1984

name/title hierarchy

Use of all levels of hierarchy also affects matching using MARS 2.0 authority name/title headings. If there is no authority record containing the complete name/title heading, any authority records for the higher levels of the heading will be matched and provided.


The matching process checks the authority record heading use codes from the authority record (008 bytes 14-16 and the type of series code 008 byte 12) to ensure that the bibliographic heading has been used appropriately:

 008 [12] – Type of series
 008 [14] – Main or added entry
 008 [15] – Subject added entry
 008 [16] – Series added entry

A report of the matches in which the bibliographic usage and the authority record authorized usage codes conflict is available (see Step 5, R11).


LC has created reference authority records, which are not authorized for use in bibliographic records. These records are identified by a value b or c in byte 9 of the 008 field. MARS 2.0 does not match bibliographic headings against an LC reference record. No heading is converted from reference authority records.


MARS 2.0 also matches bibliographic headings against authority headings in the MARS 2.0 Auxiliary File. The auxiliary file contains records with additional validated headings and additional cross-references not present in national authority files. The additional cross-references convert incorrect or obsolete forms to the authorized form of the headings. Authority records from this file are used during authority matching only and are not distributed to libraries.

For example, concentration camps were previously tagged as 651 headings, with the authority records in the LC SAF. When the tagging was changed to X10 and the authority records moved to the LC NAF, no 4XX See From tracings were added to the LC authority records for the obsolete form of the heading. The MARS 2.0 staff created records in the MARS 2.0 Auxiliary File that make the following conversion:

 bib heading:
 651  0 $a Husum-Schwesing (Germany : Concentration camp)
 changes to:
 610 20 $a Husum-Schwesing (Concentration camp)


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