Step 3.6

STEP 3.6 : SUBDIVISION UPDATES

The use of $v for form subdivisions (periodical, bibliography, etc.) was authorized in the MARC Bibliographic Format in 1995. Introduced first by NLM in MeSH headings, LC began distributing both bibliographic and authority records containing $v in February 1999.

LC STANDARD FORM

An increasing number of authority records include subdivisions coded as subfield $v. When a heading in a bibliographic record matches an authority record heading, MARS 2.0 modifies the subfield codes to conform to those in the authority record as part of the matching process:

 
 original form:
 650  0 $a English literature $x History and criticism $x Periodicals.
 
 new form:
 650  0 $a English literature $x History and criticism $v Periodicals.
 

preservation

Many libraries have begun coding form subdivisions as $v in their new catalog records. MARS 2.0 can preserve your $v codes in subject headings regardless of the existence of an LC authority record for the heading:

 
 original heading:
 650  0 $a Stocks $x Prices $v Databases.
 
 authority record sh 87003018:
 650  0 $a Stocks $x Prices $x Databases.
 

If you preserve existing $v, the original $v will be retained even though the LC authority record codes databases as $x. The heading on the bibliographic record would be your original heading:

 
 650  0 $a Stocks $x Prices $v Databases.
 

update headings

You can also elect to have all form subdivisions coded as $v:

 
 original heading:
 650 0 $a Stocks $x Prices $x Databases.
 
 authority record sh 87003018:
 650 0 $a Stocks $x Prices $x Databases.
 
 In this example, you have chosen update $x subdivisions to $v regardless:
 650 0 $a Stocks $x Prices $v Databases.
 

MARS 2.0 would convert your bibliographic heading to the new $v form whether or not an authority record contained that form. MARS 2.0 programs only modify a subfield code if the subdivision meets a number of specific conditions, set by LC and MARC 21. To be eligible for updating to $v, the subdivision must be:

• Part of a subject (6XX) heading
• The last subfield, or last pair of subfields, in a heading

Exceptions:

• Eligible subfields can be followed by geographic $z
• Eligible subfields can be followed by $x containing a language

Other exceptions are also supported by the MARS 2.0 $v system and are found in our programming set of rules. The MARS 2.0 staff has made many additional changes to other MARS 2.0 tables so that obsolete subdivisions will be updated to the correct $v form. If you have a question about a particular $v conversion, please contact your MARS 2.0 project manager.

MARS 2.0 programs apply an extensive table of over a thousand form subdivisions consisting of both single and multiple subdivisions to $v processing. This table was developed based on LC and MARC 21 form subdivision documents, plus analysis of library headings by the MARS 2.0 Authority Control team. Subdivisions that can be correctly coded by either a $x or $v are always converted to a $v if this option is selected.

A Subfield Code Changed from $x to $v report is generated for all headings containing ambiguous headings that have been flipped to $v (see Step 5.2, R39).

Two subdivisions that appear at the end of a heading are not converted to $v unless the pair has been included as an acceptable combination in the form subdivision table.

In this example, both gazetteers and bibliography can be form subdivisions:

 
 original heading:
 651 0 $a France $x Gazetteers $x Bibliography.
 

The combination of these two $x subdivisions, however, is not an authorized form subdivision, so only the final subdivision would be recoded as $v:

 
 651 0 $a France $x Gazetteers $v Bibliography.
 

AUTHORITY RECORDS

MARS 2.0 processes described previously in this section are applied to bibliographic headings only. Many LC authority records contain potential form subdivisions coded as $x.

Both preserving $v codes you enter and having MARS 2.0 update form subdivisions to the $v code will result in bibliographic headings coded differently than the established headings in LC authority records.

The following examples show some headings from bibliographic records with differing subfield coding and the form of the heading in the LC authority records, which would be distributed to the library:

 
 bib heading (cartographic material is secondary):
 651 0 $a United States $x Maps $x Early works to 1800.
 
 bib heading (work containing actual maps or reproductions):
 651 0 $a United States $v Maps $v Early works to 1800.
 
 authority sh 86006684 (valid for both forms listed above):
 151 $a United States $x Maps $x Early works to 1800
 
 bib heading (work about various collections of manuscripts):
 650 0 $a Manuscripts $x Collections.
 
 bib heading (work containing a collection of manuscripts):
 650 0 $a Manuscripts $v Collections.
 
 authority sh 85080674 (valid for both forms listed above):
 150 $a Manuscripts $v Collections