Based on the report of the Task Group on Normalization of the PCC Standing Committee on Automation, approved by the PCC Policy Committee in November 2007 and further revised April 1, 2009.
When a new authority record is added to an authority file, each heading is compared against the headings and references already in the file to determine whether the new headings and references are allowable, that is, adequately differentiated from existing headings. The headings and references already in the file and the ones to be added are normalized before comparison so that only certain characters will be considered in the comparison. The normalization rules that apply to characters are specified in Appendix A. The rules for heading comparison are given below.
Rules for Comparison
Note the following before applying the rules for comparison:
- The following rules apply after characters have been subjected to the character normalizations described in Appendix A.
- The rules apply to all name authority records that are part of the NACO program: names, corporate bodies, meetings, etc., titles/series, and name/titles. Name authority records, however, are not compared against subject authority records.
- The rules apply to LCSH subject authority records (008/11=a) that represent established headings (008/09=a) and subdivisions (008/09=d). LCSH subject authority records, however, are not compared against name authority records.
- For the purposes of these rules, 1XX fields in LCSH subject authority records for untraced and traced references (008/09=b or c) are not treated as established headings but as see references, so they should be regarded as 4XX fields in the comparisons below.
- LC subject headings for children’s literature (008/11=b) or records from other subject heading systems are excluded from these comparisons.
- Established heading linking entries (7XX fields) are not compared.
- Except as noted in 6) below, the tags of the fields do not form part of this comparison, but subfield delimiters and codes are included. Certain subfields (i.e., $i and $w in 4XX and 5XX) are eliminated before comparison.
- An established heading (1XX field) must not compare the same as any other established heading, except: an established topical heading (150 field) in one subject authority record may compare the same as an established form/genre heading (155 field) in another subject authority record.
- A see reference tracing (4XX field) must not compare the same as any established heading (1XX field) in any record.
- A see reference tracing (4XX field) must not compare the same as any see also reference tracing (5XX field) in any record.
- A see reference tracing (4XX field) must not compare the same as another see reference tracing (4XX field) in the same authority record.
- A see reference tracing (4XX field) in one authority record may compare the same as a see reference (4XX field) in another authority record.
- A see also reference tracing (5XX field) must have the same second and third tag characters and compare the same as an established heading in another authority record. For example, a 500 field in one authority record must match a 100 field in another authority record. This rule means that every 5XX field must have a matching 1XX field, but not all 1XX fields will have a matching 5XX field.
Notable Changes in this Revision
- Subfield codes are now considered as part of the comparison. This allows the same term in a 150$a and 180$x to occur without conflict because the subfield codes ‘a’ and ‘x’ will make the strings unique.
- A see reference tracing (4XX field) may not compare the same as a see reference tracing (4XX field) in the same authority record; this was allowed under the earlier rules, although the practice wasn’t followed in LCSH records.
Appendix A
Note: The characters referred to below correspond to the MARC 21 Latin-based character sets, Basic Latin (ASCII) and Extended Latin (ANSEL).
Character Normalization Tables |
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General Characters |
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Character | Character | Comments |
Leading blanks | Delete | |
Trailing blanks | Delete | |
Multiple blanks | Delete/Blank | Compress to a single blank |
Lowercase letters | Uppercase equivalent | |
Uppercase letters | Retain | |
Numbers | Retain |
Modifying Diacritics |
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---|---|---|
Character | Character | Comments |
Acute |
Delete | *Do not confuse with spacing character equivalents (see Other Special Characters below) |
Translated Characters |
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---|---|---|
Character | Character | Comments |
Superscript numbers | Numbers | Convert to non-superscript equivalent |
Subscript numbers | Numbers | Convert to non-subscript equivalent |
Diagraph AE | AE | Upper and lower case |
Diagraph OE | OE | Upper and lower case |
D with crossbar | D | Upper and lower case |
Eth | D | Upper and lower case |
Lowercase Turkish i | I | |
Polish L | L | Upper and lower case |
Script small L | L | |
O Hook | O | Upper and lower case |
U Hook | U | Upper and lower case |
Scandinavian O | O | Upper and lower case |
Icelandic Thorn | TH | Upper and lower case |
Eszett symbol | SS | Do not use in NACO records |
Greek alpha | Uppercase Greek alpha (U + 0391) |
Do not use in NACO 1XX fields |
Greek beta | Uppercase Greek beta (U + 0392) |
Do not use in NACO 1XX fields |
Greek gamma | Uppercase Greek gamma (U + 0393) |
Do not use in NACO 1XX fields |
Punctuation |
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---|---|---|
Character | Character | Comments |
Exclamation mark | Blank | |
Quotation mark | Blank | |
Apostrophe | Delete | |
Opening parenthesis | Blank | |
Closing parenthesis | Blank | |
Hyphen, minus- | Blank | |
Opening square bracket | Delete | |
Closing square bracket | Delete | |
Opening curly bracket | Blank | |
Closing curly bracket | Blank | |
Less-than sign | Blank | |
Greater-than sign | Blank | |
Semicolon | Blank | |
Colon: | Blank | |
Period, decimal point | Blank | |
Question mark | Blank | |
Inverted question mark | Blank | |
Inverted exclamation mark | Blank | |
comma | Comma or blank | The first comma in $a is retained; all other converted to blank |
Content Designation |
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---|---|---|
Character | Character | Comments |
Indicators | Delete | |
Subfield delimiters | Retain | |
Subfield codes | Retain | |
Tag | See comparison rules | |
Joiner, Non-joiner, Unicode Formatting Characters | Delete |
Changes in this Revision |
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---|---|---|
Character | Old Conversion | New Conversion |
Commercial at sign | Blank | Retain |
Vertical bar | Delete | Blank |
Dollar sign | Blank | Retain |
British pound sign | Blank | Retain |
Middle dot | Delete | Blank |
Greek alpha | A | Uppercase Greek alpha |
Greek beta | B | Uppercase Greek beta |
Greek gamma | G | Uppercase Greek gamma |
Subfield codes | Delete | Retain |
Last update: Apr. 9, 2020