Merging duplicate cartographic resources records: A field-by-field comparison
1. Introduction
Complete instructions are to be used in conjunction with BFAS Chapter 4, “When to Input a New Record” (http://www.oclc.org/bibformats/en/input.html), which has been thoroughly revised. Please contact OCLC Metadata Quality staff regarding any questions at askqc@oclc.org.
Please contact OCLC Metadata Quality staff regarding any questions at askqc@oclc.org.
- When a record has internal inconsistencies, especially between coded and textual data, tend to favor textual data or a dominance of evidence, when appropriate.
- Apply looser criteria if the duplicate record is a vendor record or is batch-loaded (Encoding Level M) and has not been edited by another library.
Rare Cartographic Materials (pre-1901)
Note: Catalogers unfamiliar with the rare cartographic materials and rare cartographic material cataloging rules should not merge bibliographic records for either original rare cartographic materials or their electronic reproductions. When considering the merging of records for electronic reproductions of rare cartographic materials, take into account the additional electronic resource guidelines in Appendix A of Merging Duplicate Books Records.
Cartographic items that are published prior to 1901 are by default considered rare. However, rare cartographic material cataloging rules can be applied to items regardless of date of publication, and any item cataloged according to such rules should be considered rare. Rare cartographic material cataloging rules are coded in the 040 subfield $e (e.g., dcrmc).
The full list of descriptive conventions is: amin, amremm, appm, bdrb, cgcrb, cco, dacs, dcarlisnaaf, dcgpm, dcrb, dcrmb, dcrmc, dcrmg, dcrmm, dcrmmss, dcrms, dcrmr, dmbsb, enol, estc, fiafcm, gihc, hmstcn, iosr, kam, nmxcmdf, ohcm, rad, rna, rnab, vd16, vd17.
2. Fixed field
2.1. Type/BLvl
Should match but be aware of incorrect coding.
2.2. CrTp
The type of cartographic material should match but be aware of incorrect coding.
2.3. Form
The form of item being described should match but be aware of incorrect coding.
2.4. Proj
The type of projection code should match and correspond to the projection statement provided in field 255 but be aware of missing or incorrect coding.
2.5. Relf
The code(s) for relief should match and correspond to the relief statement provided in field 500 but be aware of missing or incorrect coding.
2.6. SpFm
The code(s) for special format characteristics should match and correspond with the characteristics provided in field 300 or field 500 but be aware of missing or incorrect coding.
2.7. DtSt and dates
Use judgment on dates. Be aware of practices that have changed over time regarding the recording of uncertain, questionable, and unknown dates, as well as the different decisions that may be made in those instances. See also fields 260/264 subfield $c to make sure that they correspond.
3. Variable fields
3.1. 006 and 007
Records may be considered duplicates for merge even with the absence or presence of fields 006 or 007.
Specific differences in the physical format of the item may justify leaving the records separate.
3.2. 010
Records may be merged regardless of the absence of presence of a 010 field. Records with a difference in control numbers issued by the same agency may be potential duplicate records. Compare fields 245 through 6xx to justify a merge.
Do not merge two DLC records with different LCCNs if neither is ELvl "J". Report these to AskQC. Otherwise, add the LCCN from the ELvl "J" record in subfield $z to the 010 field of the retained record.
3.3. 020
Absence or presence of field 020 does not justify a separate record. Although ISBNs should match, be aware that multiple ISBNs may apply to the same item. Different 020 fields alone do not justify separate records. The records could still be potential duplicates to be merged. Compare fields 245 through 5xx to justify a merge.
3.4. 034
The cartographic mathematical data, scale, projection, and/or coordinates should match, if present. Be aware of missing or incorrect data. See also field 255.
3.5. 041
Absence or presence of field 041 does not justify a separate record. Differences in field 041 alone do not justify a separate record. Compare fixed-field Lang and fields 130, 240, 245, 250, 5xx, and 7xx with special attention to fields 250 and 5xx. Specific differences in the language of the item justify a separate record. See also Lang and field 546.
3.6. 043
Absence or presence of field 043 does not justify a separate record. Differences in field 043 alone do not justify a separate record. Compare fields 65x. Specific differences in geographic codes for the item may justify a separate record. Compare fields 245 through 6xx to justify a merge.
3.7. 052
Absence or presence of field 052 does not justify a separate record. Differences in field 052 alone do not justify a separate record. Compare fields 245 through 65x to justify a merge. Specific differences in the geographic area covered by the item justify a separate record.
3.8. 1xx
Records may be considered duplicates for merge even with the absence, presence, or difference in choice or form of the 1xx field. Compare fields 245 subfield $c, 5xx, and 7xx.
3.9. 245
Subfield $a should match but be aware that some variations in the title proper may be due to differences in the source of information, or cataloger's interpretation of title layout, or choice made for title proper when two or more titles are present, any of which may be noted in field 500.
Subfields $b, $n, and $p may be cataloger's interpretation. Use judgment.
Subfield $c should have the same statement of responsibility. In cases of multiple statements of responsibility, the order of statements can be different, but the responsibilities must match.
- $c this publication produced by Hart Enterprises, Inc. ; compliments of the City of Laredo and the Laredo Chamber of Commerce matches $c compliments of the City of Laredo and the Laredo Chamber of Commerce ; this publication produced by Hart Enterprises, Inc.
Two records can be merged if there is a typo difference in the title and it is clearly a typo as opposed to an alternate spelling (i.e., color vs. colour).
3.10. 250
Editions should match when present on all records. Compare fields 245 through 5xx for other differences to justify a merge.
Note: You may merge if one says "1st edition" and other has no edition statement present on the record.
Do not merge:
- If one record has "Revised edition", "2nd edition", "3rd edition", etc. and the other does not have an edition statement.
- If one record has an edition statement that makes the item unique and the other record has no edition statement.
Compare fields 245 through 5xx for other differences to justify a merge.
3.11. 255
Subfield $a
- Statement of scale should match. Be aware of possible differences in the results based on the use of a natural scale indicator or similar device – use judgment.
Subfield $b
- Statement of projection should match. Be aware that this information could also be recorded in field 500.
Subfield $c
- Statement of coordinates should match. Be aware of possible differences in measuring – use judgment.
- Absence or presence of coordinates do not justify separate records. Compare fields 034 and 255 to justify a merge.
Subfields $d, $e, $f, and $g
- Statements should match if present.
3.12. 260/264 - Atlases
Subfield $a
- Absence or presence of field 260 subfield $a, field 260 subfield $e, or field 264 subfield $a does not justify a separate record. Generally, if the first named place reflects a different country, separate records are justified.
- New York matches New York ; $a Toronto
- London ; $a Orlando matches London ; $a Toronto
- Hamburg, Germany does not match New York ; $a Hamburg, Germany
- California ; $a London does not match London ; $a California
Note: Places of publication within the same country are considered a match
- New York ; $a London matches Chicago ; $a London
- If one record has "[Place of publication not identified]" and the other has a place provided in brackets, consider them duplicates for merging if all else matches on the records
Examples:
[Place of publication is identified]
matches
[London] or [London?]
- See also fixed-field Ctry code
Subfield $b guidelines
- Publisher should match but be aware of:
- Variations in choice among multiple publishers, distributors, or manufacturers (including printers) due to perceived ambiguity of prominence rather than actual differences in order
- Variations in choice among multiple publishers, distributors, or manufacturers (including printers) when the roles of those entities may be ambiguous
- Variations in fullness of the name of the publisher, distributor, or manufacturer (including printer)
- Rand McNally matches R. McNally or Rand McNally and Co.
- Henry Teesdale & Co. matches H. Teesdale & Co.
- If any of the above variations appear to apply and all else matches on the records, generally consider them duplicates for merging
- If one has "[Publisher not identified]" but the other has a publisher provided in brackets, consider them duplicates for merging if all else matches on the records
Example:
Chicago : $b [Publisher not identified]
matches
Chicago : $b [University of Chicago Press]
- Do not merge if the publisher's name changed.
Subfield $c guidelines
- Use judgment on dates. Be aware of changing practices regarding the recording of uncertain, questionable, and unknown dates, as well as the different decisions that may be made in those instances
- Variation in, or absence of, copyright dates should be disregarded in cases where the dates of publication are the same.
- 2015 matches 2015, ©2014
- Printing dates are not considered dates of publication and should usually be ignored
- If one record has "[date of publication not identified]" and the other has a date or partial date provided in brackets, with or without a question mark, they may be considered duplicates for merging if all else matches on the records
Examples:
[date of publication not identified] may match [2015?]
and
[date of publication not identified] may match [19--?]
and
[date of publication not identified] may match [199-?]
and
[date of publication not identified] may match [2014]
and
[date of publication not identified] may match [2---?]
- If one record has questionable dates in brackets with or without a question mark or specifies a range of dates, and the other gives a specific date within that range, they may be considered candidates for merging if all else matches on the records
Examples:
[20--?] may match [2015] – same century
and
[199-] may match [1995] – same decade
and
[194?] may match [19--?] – both questionable dates
- It is usually best to not merge records representing items from different centuries or decades, even if everything else seems to match, but use judgment
Examples:
[19--?] does not match [189-?] – different centuries
and
[197-?] does not match [199-?] – different decades
and
[199-?] does not match [2000] – different decades
260/264 - Maps
Subfield $a
- Absence or presence of field 260 subfield $a, field 260 subfield $e, or field 264 subfield $a does not justify a separate record
- If one record has "[Place of publication not identified]" and the other has a place provided in brackets, consider them duplicates for merging if all else matches on the records
Example:
[Place of publication not identified] matches [London]
- See also fixed-field Ctry code
Subfield $b guidelines
- Publisher should match but be aware of:
- Variations in choice among multiple publishers or manufacturers (including printers) due to perceived ambiguity of prominence rather than actual differences in order
- Variations in choice among multiple publishers or manufacturers (including printers) when the roles of those entities may be ambiguous
- Variations in fullness of the name of the publisher or manufacturer (including printer)
- Rand McNally matches R. McNally
- If any of the above variations appear to apply and all else matches on the records, generally consider them duplicates for merging.
- If one has "[Publisher not identified]" but the other has a publisher provided in brackets, consider them duplicates for merging if all else matches on the records
Example:
New York : $b [Publisher not identified] matches New York : $b [American Map Company]
- Do not merge if the publisher's name changed.
Subfield $c guidelines
- Use judgment on dates. Be aware of changing practices regarding the recording of uncertain, questionable, and unknown dates, as well as the different decisions that may be made in those instances.
- Variation in, or absence of, copyright dates should be disregarded in cases where the dates of publication are the same.
- 2015 matches 2015, ©2014
- Printing dates are not considered dates of publication and should usually be ignored.
- If one record has "[date of publication not identified]" and the other has a date or partial date provided in brackets, with or without a question mark, they may be considered duplicates for merging if all else matches on the records
Examples:
[date of publication not identified] may match [2015?]
and
[date of publication not identified] may match [19--?]
and
[date of publication not identified] may match [199-?]
and
[date of publication not identified] may match [2014]
and
[date of publication not identified] may match [2---?]
- If one record has questionable dates in brackets, with or without a question mark, or specifies a range of dates, and the other gives a specific date within that range, they may be considered candidates for merging if all else matches on the records
Examples:
[20--?] may match [2015?] – same century
and
[199-?] may match [1995] – same decade
and
[194?] may match [19--] – both questionable dates
- It is usually best to not merge records representing items from different centuries or decades, even if everything else seems to match, but use judgment
Examples:
[19--?] does not match [189-?] – different centuries
and
[197-?] does not match [199-?] – different decades
and
[199-?] does not match [2000] – different decades
300 - Atlases
Subfield $a
- Number of pages may vary by 3 (when the total number of pages exceeds 10) and still be considered a match, if all else matches on the records.
- 1 atlas (25 pages) may match 1 atlas (27 pages)
- Variations in paging due to different methods used to record paging may be ignored, if all else matches on the records.
Examples:
1 atlas (various pages) may match 1 atlas (12, 28, 3 pages)
and
1 atlas (unpaged) may match 1 atlas [any number of pages in brackets]
and
1 atlas may match 1 atlas [any number of pages in brackets]
and
1 atlas (473 pages) may match 2 volumes in 1 [473] – gives number of pages
and
Approximately 18 maps may match [18 maps]
- If one record has a number of pages or maps and the other has a number of volumes or sheets greater than one, they are not considered duplicates.
- 3 v. does not match 3 v. in 1
- 1 atlas (473 pages) does not match 1 atlas (2 v. in 1) – i.e., pages are not given
Subfield $b guidelines
- Absence or presence of illustrations does not justify a new record. Records may be merged if one has illustrations and the other does not. Specific differences in illustrations (color vs. black and white) justify a separate record.
Subfield $c guidelines
- Use judgment on size. Size may vary by no more than 2 cm if all else matches on the records.
- 35 cm matches 37 cm – within allowable range
Subfield $e guidelines
- Absence or presence of subfield $e that indicates substantive accompanying material may justify a new record. The accompanying material may be cataloged separately or described in a note. Compare fields 006 through 5xx to justify a merge.
Example:
300 1 atlas (212 pages) ; $c 27 cm + $e 1 teacher’s notes (20 pages)
matches
300 1 atlas (212 pages) ; $c 27 cm
500 Includes teacher’s notes (20 pages).
- Do not merge those with a difference in subfield $e.
Example:
300 1 atlas (415 pages) ; $c 34 cm + $e 1 CD-ROM.
does not match
300 1 atlas (415 pages) ; $c 34 cm
(Record has no indication that the item has accompanying CD-ROM)
3.13. 300 - maps
Subfield $a
- Number of main maps should match.
- Number of sheets should match.
- 20 maps may match 20 maps on 16 sheets – use judgement. Compare fields 245 through 6xx to justify a merge.
- 5 maps on 1 sheet ; $c 43 x 33 cm or smaller, sheet 75 x 60 cm matches 5 maps ; $c on sheet 75 x 60 cm
Subfield $b guidelines
- Absence or presence of other physical details (layout, production method, color, material, and mounting) does not justify a new record.
- $b color may not match $b color, on silk – use judgement. Compare fields 245 through 6xx to justify a merge.
Subfield $c guidelines
- Use judgment on size. Be aware of different elements regarding measurements (neat line, border, margin, or sheet) as well as the different decisions that may be made in recording that information. Size may vary by no more than 5 cm, if all else matches on the record.
- $c 22 x 59 cm matches $c 25 x 62 cm, folded to 22 x 10 cm – within allowable difference
Subfield $e guidelines
- Absence or presence of subfield $e that indicates substantive accompanying material may justify a new record. The accompanying material may be cataloged separately or described in a note. Compare fields 006 through 5xx to justify a merge.
Example:
300 1 map ; $c 21 x 58 cm + $e 1 booklet (36 pages ; 21 cm)
matches
300 1 map ; $c 21 x 58 cm
500 Accompanied by text: 36 pages ; 22 cm.
- Do not merge those with a difference in subfield $e. Compare fields 006 through 5xx to justify a merge.
Example:
300 1 map ; $c 66 x 55 cm + $e 1 text (168 pages ; 24 cm)
does not match
300 1 map ; $c 66 x 55 cm
(Record has no indication that the item has accompanying text)
3.14. 490 and 8xx
Absence or presence of a series statement does not necessarily justify separate records. Compare fields 245 through 5xx for series information. Guidelines regarding series retention can be found in the Record Merge Field Transfers document.
Examples of situations that may justify separate records, use judgment.
- Variation in form of series statement
- Variation in tracing decision or form (i.e., 490 vs. 490 with 830)
- Absence, presence, or difference in series statement of responsibility
- Change of series among issues or parts of a serial or multipart item. Do not merge if the item is issued in a different series.
3.15. 500
Absence or presence of numerical or alpha-numeric identifier does not necessarily justify separate records. Compare fields 245 through 5xx to justify a merge.
Example:
245 10 Africa, $n 803535AI (G00392) 6-12
matches
500 “803535AI (G00392) 6-12.”
501
The use of field 501 implies that there must be separate bibliographic record(s) for the resource(s) described following "With:" and that when all of those records are considered together, they describe the complete resource. If cataloged correctly, each of those records would describe only part of the complete resource, a fact that would be reflected in the 300 field.
- Records may be merged regardless of the presence or absence of fields 501 only if they represent the same complete resource, with fields 300 matching (according to the field 300 criteria) and all constituent parts of the resource being accounted for in fields 245, 505, and or 1XX/7XX
- In current cataloging, field 501 is primarily for rare, historical, and other special materials
- Field 501 would not properly be used to show local binding practice and does not justify a separate record in such cases
3.16. 533
Do not merge if one has 533 and other does not, unless the records represent electronic resources. Some older records have 533 information in a 500 field. Do not merge if the series differ. Make sure type, place, and agency of reproduction matches.
3.17. 6xx
Records may be considered duplicates for merge even with the absence, presence, or difference in 6xx fields and if all else matches on the records. Compare fields 245 through 5xx to justify a merge.
3.18. 7xx
Records may be considered duplicates for merge even with the absence, presence, or difference in 7xx fields.
4. Exceptions
4.1. Merging Parallel Records in Connexion Client
Records for the same title, but cataloged in different languages, such as English, Spanish and French, are not considered duplicate records, but are considered parallel records.
Examples:
A library with Spanish as the language of cataloging, that finds only an English record in WorldCat, may enter a Spanish language of cataloging record.
A library with English as the language of cataloging, that finds only an Italian record in WorldCat, may enter an English language of cataloging record.
Subfield $b should be present, but is not always, in records created by libraries for which English is not the language of the cataloging agency and is coded in field 040 (Cataloging Source) of the record. Therefore, it may be necessary to check the rest of the record to determine the language of cataloging and add the 040 $b if needed.
Examples:
040 LGP $b cze $c LGP
040 FLD $b fre $c FLD
A good way to determine the language of cataloging is by the language of the notes (5xx) fields.
Examples:
504 With street directory and by-pass. 504 Mit Straßenverz. und Nebenkt. (German)
504 Con directorio de calles y by-pass. (Spanish)
If no notes fields are present in the record, another field that can be referenced is the 300 $a.
Examples:
300 1 map (French "carte"; German "karte"; Spanish "mapa"; Dutch "kaart")
Be aware that the 040 $b present in the record cannot always be trusted. An example would be that the cataloging is English, but the 040 is coded "spa" because the institution that did the cataloging is Latin American. In this example, report the records to askqc@oclc.org for further investigation and correction.
4.2. Guidelines for Comparing LC PCC and Member PCC Records
Both records will have 042 field 'pcc'. If the records are determined to be duplicates, retain the most complete record based on content, NOT the number of fields.
4.3. UKM CIP (Cataloging-in-Publication) Guidelines - Atlases
UKM CIP records are either encoding level 8 pre-publication records, or encoding level M records with symbol UKMGB, created by the British Library.
UKMGB are newer records. Consider UKMGB as equivalent to encoding level 8 if they have "p. cm" or "pages cm" in the 300 and have a 263 field. There are looser criteria for merging UKM CIP records with other records. These records usually contain variations in fields 245, 260 subfield $a and subfield $c, 300, and the 4xx fields.
The 300 fields, if present in encoding level 8 records, are pre-publication estimates and should not be interpreted as actual paginations and sizes. This field is often incomplete or still blank, i.e. 300 p. cm.
The 260 or 264 subfield $a, place of publication, is another field that will usually differ. In most instances, this is not a factor and the records can be merged.
Example:
CIP and UKM full level records each contain a place of publication with the difference being the country of publication and they both clearly represent the same item (same ISBN for example); these can be merged with no question.
4.4. Vendor records
There are looser criteria for merging records from vendors that are less-than-full level (encoding level 3, M, K, etc.). They are very brief in content; usually consisting of a title, publisher, date, and ISBN.
These records are candidates for potential merging with other records.
Please refer to the Vendor list for merging document for a list of the vendors and additional guidelines for merging.
Revision history
| Date | Last edited by | Description of changes |
|---|---|---|
| 30 June 2020 | Shanna Griffith | Deleted Rare Materials section from the Exceptions section Added revised Rare Materials guidelines to Introduction section |
| 08 Dec 2020 | Shanna Griffith | Revised 501 section |
| 26 May 2022 | Shanna Griffith | Revised restrictions for merging rare cartographic materials and moved up to the beginning of the Rare materials (pre-1830) section. Corrected formatting of examples and other cosmetic changes. |
| 06 June 2022 | Shanna Griffith | Updated date for rare cartographic materials from pre-1830 to pre-1901 |
| 11 Nov 2022 | Shanna Griffith | Added the 7 more recently validated Description Convention Source Codes to the Rare Materials (pre-1901) section:
|