Authority Control at LTI

What is Authority Control?

Bibliographic control in a library catalog is accomplished by the assignment of a unique form of a heading and the use of cross-references from unused and related headings. Selecting a single form brings together in one place all the works of an author, editions of a work, titles in a series, and subjects dealing principally or exclusively with a topic. Through the use of see and see also references, authority control creates a syndetic structure that guides the user to the materials sought. The see reference tells the user that the information being sought is to be found not under that heading, but rather under a different (i.e., the "authorized") heading. See also references show relationships between headings. The two concepts of heading uniqueness and cross-referencing are the pillars of authority control. Together they make possible efficient access to library resources.

Why has authority control become increasingly important to libraries?
In the past, library administrators have viewed authority control as a desirable element in the cataloging process, but one so costly in professional staff time as to be justifiable only in research institutions. These days the ubiquity of Integrated Library Systems (ILS) in all types and sizes of libraries belie the notion that authority control is a luxury.

Widespread implementation of on-line catalogs revealed what card catalogs so effectively concealed. Namely, that most card catalogs were plagued with "divided file" headings, archaic subject terms and place names, non-existent or inadequate cross-references, and otherwise misleading headings. Changing cataloging rules, reliance on shared cataloging from bibliographic utilities, and, until recently, the catalog's physical form, have all contributed to the problem of maintaining current and consistent name and subject headings. Many of the problems found in card catalogs were carried over into online catalogs, particularly if the library's records were never authorized, or authorized poorly.

Fortunately, Online Public Access Catalogs (OPACs) not only reveal problems that remained hidden in card catalogs, but the machine-readable records from which the ILS is created make possible a level of authority control superior to anything that could be achieved in non-computerized catalogs.

Authority control is essential for effective local system searching.
It improves access dramatically by providing consistency in the form of headings used to identify authors, place names, uniform titles, series, and subjects. Equally important are logical linkages between names and concepts. Keywords, combined with Boolean operators, offer powerful supplemental search capabilities, but they are no substitute for authority control. The collocation functions of a library catalog go well beyond its "finding list" functions and can only be met by traditional authority control.

Although library users are the principal beneficiaries of enhanced access resulting from authority control, authorized headings and display of cross-references within a local system reduce the work of technical services librarians responsible for building and maintaining the catalog. There is a price to be paid for good authority control, but an even bigger price to be paid for not having good authority control. Participation in resource sharing networks, cooperative ventures such as NACO, dependence on Internet connectivity, and recent trends in "outsourcing" technical services operations are also strong arguments for libraries to ensure that headings adhere to national bibliographic standards.

Steps in Authority Control

Authority control generally takes place following all other database work, e.g., duplicate record resolution, merging bibliographic records of multiple libraries into a single database, etc. Libraries migrating from one local system to another often take this opportunity to re-authorize their bibliographic records and obtain a clean file of up-to-date authority records prior to implementing the new system.

From a processing perspective, batch authority control is achieved through a series of clean-up operations.

  1. Headings are “normalized” for spacing and punctuation to increase the probability of a link between a bibliographic record heading and an authority record heading.
  2. The normalized headings are then compared against a comprehensive index of authorized and variant-form headings generated from authority records.
  3. When a match occurs, a link is created between the authority record heading and the bibliographic record heading.
  4. If the bibliographic record heading matches a variant form (tag 4XX) in an authority record, the bibliographic record heading is replaced by the contents of the authorized access point in the authority record (tag 1XX).

Ideally, all headings in the library's database should match an LC authority record, but in practice some headings do not link. The vendor responsible for authority control must do everything possible to increase links between bibliographic record headings and authority records while avoiding false matches.

After all possible headings are matched to an authority record, they are inserted back into the bibliographic records.
That is, the authority record heading replaces completely the bibliographic record heading. Along with the post-processed database of bibliographic records, the linked LC authority records are extracted and returned with the bibliographic records for loading into the local system's authority module. Authority records returned to the library are collection-specific. The local system builds its index tables from both the controlled headings in the bibliographic records and the see and see also cross-references present in the LC authority records.

The number of bibliographic records returned is the same as the number of source records to be authorized. Prior to loading the new, comprehensive replacement authority records, the library will want to delete all existing LC and local authority records. In other words one wants to 'overlay' the newly authorized bibliographic records, while authority records need to be completely replaced. During the period while the database is being authorized staff may continue to catalog new titles; however, they should avoid making changes to existing catalog records. This restriction does not apply to item record data-e.g., location codes, barcode numbers, etc.

Depending on the local system, the library may want brief or "provisional" authority records created for headings either not matching, or not fully matching, an LC authority record. These are skeleton authority records containing the unverified heading and default data. Provisional authority records do not contain cross-references and are of limited use since most modern local systems are capable of generating such authority records from unlinked headings.

Following batch authority control, a library is confronted with two challenges in keeping its catalog headings up-to-date and consistent.
The first is to ensure that headings from new bibliographic records being added to the database are authorized. Options for controlling new headings include: 1) authorize them manually at the time of cataloging prior to loading the new bibliographic records into the database; 2) make no attempt to authorize new headings at the time of cataloging or record load, but periodically export and submit newly added bibliographic records to the authority control vendor for batch authority processing; or, 3) use an FTP-based service to transmit new records to the authority control vendor in batches on a regular (e.g., weekly, biweekly) or irregular basis.

A second challenge in keeping a library's headings in harmony with authorized headings is controlling for new and revised authority records issued after the library's records were batch processed. To help catalogers keep abreast of these additions and changes, authority control providers offer services alerting customers to the issuance of new and changed LC authority records affecting headings in the library's database.

Unless the library views authority control as a one-time event (i.e., it has no interest in maintaining control over headings after the batch authority control is finished), the availability of a comprehensive update service should be an important consideration when selecting an authority control vendor. LTI provides two services, Authority Express and Authority Update Processing, that work hand-in-hand to meet these needs. Details on these services can be found in our Continuing Authority Control section.

The LTI Difference, pt. 1: Dedication to Detail

Given the enormous variation that exists among vendors in the thoroughness and quality of their authority control processing, LTI takes the position that customers have the right to know in advance what is being purchased.

What's Included In LTI's Authority Control Processing
LTI's authority control processing includes filing indicator fixes; pre-processing fixes and MARC updates; machine linkage of headings to authority records, including limited manual review of headings that remained unlinked following machine processing; final re-linking; and writing of bibliographic and linked authority records to separate files for transmittal to the library or its local system vendor.

Each step in the authority control process is designed to maximize authority record links and to eliminate incorrect links. Where the full heading in the catalog record cannot be validated or linked to an authority record, LTI attempts to link portions of the heading. In addition, every batch or backfile receives limited review by professional librarians for links that could not be machine-identified.

In batch processing, LTI guarantees that 95% or more of the customer's controlled headings will be linked to either an LC or LTI authorized access point. This assumes, of course, that the library has tried to adhere to national cataloging standards. Typically, about 93% of the headings link to LC authority records and 4% to LTI authority records. If less than 95% of the library's controlled headings link to an authority record, LTI performs further review to raise the overall heading link rate to 95% at no cost to the customer.

In most library databases, we find that with minimal processing about 70% of the normalized headings will match exactly with a 1XX field, or a 4XX pointing to a 1XX, in an LC name or subject authority record. In other words, provided the authority control vendor does not introduce problems that destroy links, with minimal effort any vendor should be able to link seven out of ten library headings to LC authorized access points.

How LTI Gets Such a High Link Ratio
An important factor in LTI's high link ratio of library headings to LC authority record headings is the large number of headings linked via machine based on 25 years of collecting and analyzing several hundred million bibliographic headings.

LTI compares, validates, and updates library headings by computer programs and fix tables. They use a combination of fuzzy logic and "fix and loop" routines to manipulate and repeatedly test headings against authorized access points. Depending on the type of heading (personal name, preferred title, topical subject, etc.), unlinked headings go through a cycle of routines designed to make high precision full or partial links to authorized access points. Often headings can be validated fully with an authorized access point only after one or more fixes are made to subordinate units.

LTI's fix procedures and tables are based on well defined rules of what constitutes a valid and invalid heading, as well as on empirical analysis of errors that have appeared in library headings processed by LTI over the past 25 years. For example, the subject subdivisions "United States" and "Description and travel" are each represented by hundreds of variations (e.g. Untied States, Description & travel) in subject subdivision fix tables. LC weekly authority record files and current cataloging rules are scrutinized also for changing patterns of usage. Headings that cannot be validated against an LC authority record are checked against 4.8 million LTI-created cross-references from incorrect headings to the authorized LC access point. Our files include over one hundred cross-references (i.e., in this case variant forms and misspellings) for the composer "Tchaikovsky," for instance. If an LC link cannot be made, the heading is matched against a supplemental file of 2.4 million LTI authority records.

Diacritics and special characters are retained in the match key. LTI's normalized headings also retain delimiters and subfield codes. This permits the construction of programs that check for links with and without all subfields in the heading. For example, if a personal name heading that contains $c and $d fails to link with an LC authority record, the library's heading is tested for linkage without the subfield $c, and the $d is also checked for permissible variations. For example, the birth dates $db. 1952, $dborn 1952 and $d1952- are all considered equivalent.

We also recognize that every backfile authorization project benefits from some level of editor review. LTI's experienced librarians have devoted years to analyzing why headings do not link, what processing is needed to achieve links, and what changes are needed to bring unlinked headings into conformity with current cataloging standards. High frequency unlinked headings are always examined. Single-occurrence unlinked headings are reviewed if they fall into one of many categories of “problem” headings. Problem headings are software-identified and include a range of data and content designator errors. Examples are detection of a music subfield code ($m,$r,$o) without the presence of a title subfield, a series that lacks a title, a birth date that falls after a death date, etc.

What About Full Manual Review?

As indicated above, every batch or backfile authorization project undergoes limited editor review for headings that could not be linked via computer. In full manual review, every unauthorized heading that remains after machine processing is reviewed by an editor. Given LTI’s high level of linking with limited review, full review is not considered a cost effective approach for most libraries. If during machine or limited review processing 96% of the library's subject headings are validated against authorized headings, the potential of increasing the link rate by several percentage points probably will not merit the additional expense.

Prior to offering a full manual review authority control cost quote, LTI requires that the library submit its entire database for a no-charge evaluation. If analysis shows that the library's cataloging is not consistent with U.S. national cataloging standards and practices, full manual review is not available as an option.

The LTI Difference, pt. 2: The Perils of Machine Processing

Regardless of whether a library selects limited or full review processing, controlled headings are extracted from bibliographic records and first run through machine processing. It is only after a library heading has not linked to an authorized heading during machine processing that the heading becomes a candidate for review by an editor. Thus the theory that full review would prevent "Madonna" from being confused with "Mary, Blessed Virgin, Saint" is erroneous.

The critical point is that if a heading is mis-linked during machine processing, that heading will never come to the attention of an editor because it has successfully (albeit incorrectly) linked to an authorized access point. Editors do not check every linked heading in every record to verify that a proper and correct link has been made. Instead, they examine only those headings that failed to link to an authorized heading during machine processing. If editors reviewed every heading linked during machine processing, the authority control vendor's costs might easily exceed one dollar per record. Few libraries could afford authority control at that price.

LTI is Very Selective in Its Blocking of Headings
There are thousands of bad or ambiguous LC cross-references that need to be 'blocked' prior to linking headings during machine processing. LTI blocks any heading containing five or fewer characters from linking during the initial machine link. Selectively, some of these headings are unblocked [e.g., Asia, Iran, Iraq, etc.] where there is no likelihood of an incorrect link being made to an authority record. If blocked by LTI, these headings appear in the unlinked headings list and, if the library believes the authority record is important to its catalog-for example when it contains a useful cross reference or explanatory note-the authority record can always be downloaded from LC.

Taken together, in the LC name and subject authority files there are over 11 million 1XX headings and 4XX (see from) references, of which LTI blocks 163,000. Four out of five of the blocks involve corporate/conference heading cross-references (41X). For example, the initials AAS appear as cross-references in 20 LC authority records, including those for the African Academy of Sciences, American Arachnology Society, Aquaculture Advisory Service, etc. Neglecting to block ambiguous headings and cross references can lead to some odd mislinks.

For instance, we received a bibliographic record with the following heading:
610 2 $aInternational Society for Augmentative and Alternative Communication,$cthe patriarch,$xJuvenile literature.

The pre-authorized heading probably read:
600 0 $aIsaac,$cthe patriarch,$xJuvenile literature.

We also received a bibliographic record with the following heading:
110 2 $aBiblioteca Estadual Celso Kelly.$c(Musican)

The pre-authorized heading probably read:
100 0 $aBeck$c(Musician)

Similar problems result when authority control vendors use tables to expand parts of headings during a pre-processing procedure, without taking into account the entire heading. For example, for years one vendor routinely changed the geographic subdivision $zMelbourne to $zMelbourne (Vic.) when in fact many of the headings referred to the city in Florida.

Unfortunately, once a heading has been mis-linked, a subsequent vendor will find it almost impossible to identify and to fix such headings. They are encountered only by chance or the presence of invalid subfield codes.

The LTI Difference, pt. 3: "But My Local System Has Authority Control"

By definition authority control demands a single "authority." In using LTI’s authority control services, a library has paid for and received the best authority control available to libraries today. If the library then uses its local system’s own “authority module” that flips headings based on 4XX fields in authority records, this can undermine the advanced algorithms and tables that were used to authorize the library’s database.

LTI users report strange things when they “turn on” their local system’s authority control module. For example, the library may come across an inordinate number of headings tagged as subjects but that are in fact preferred titles or series. While a series may on rare occasions be used as a subject, it is most uncommon, and it is never permissible along with the presence of form ($v), topical ($x), period ($y), or geographic ($z) subdivisions .

If these rules are ignored, however, you can end up with:

$aRomance languages $x Modality

$aAmerican university studies.$nSeries II,$pRomance languages$xModality.

because the authority record for "American university studies. Series II. Romance languages," has a 430 variant title of "Romance languages".

LTI's processing protects against this type of incorrect tag level change and, if not linked correctly by our code or editors, at worst the above headings appear in the unlinked headings list.

Such problems appear to be present in all databases where the library uses an authority control module made available by its ILS vendor. Mangled headings are not limited to any particular ILS. Regardless of local system, LTI strongly advises that ILS automatic changes to bibliographic record headings based on authority records be disabled.

The culprit is that local system authority control modules rely on the presence of the "old" heading as a 4XX field in an authority record. Not only does LC frequently not carry over the "old" heading, even if it did there may be other issues in linking the "old" heading because of variations in capitalization, spacing, or punctuation occurring, in either catalog record headings or in LC authority records. We see and report dozens of such errors in LC records each week. In addition, changes that affect free-floating subdivisions cannot be made unless an explicit authority record exists for the whole heading, so the work in identifying these cases falls to staff.

There are many instances in which a link should not be made. While LTI processing results in the highest link rate of any authority control vendor, avoiding bad links demands even more vigilance. Presently, we block over 187,000 headings in authority records (mostly 4XX fields) from linking to any catalog record heading because of the likelihood of introducing an error in a library's file. Other heading changes are limited to only certain types of linkages-i.e., there must be additional data present before the link is allowed.

LTI's refined and tested routines not only prevent bad changes from occurring, they also make thousands of needed revisions that are not possible with a simple routine that flips headings if a 4XX field with matching text is found in any authority record. Internal studies have shown that reliance on the LC record alone misses one-half to two-thirds of the needed changes. In short, when judiciously used, your library's ILS authority control module is perhaps better than none at all, but is certainly no replacement for a comprehensive batch and continuing authorization service.

Details of LTI's Authority Control Processing

Record Load

Regardless of database size, FTP is the standard method to receive and return bibliographic and authority record files. A portal for file transfer is available here on LTI's website. Records are accepted in either MARC-8 or Unicode (UTF-8) character encoding format. Bibliographic records are returned to the library in the same format they were received. At this time LTI returns LC authority records only in MARC-8. Internally, prior to matching headings against LC authority records, we first convert controlled headings from Unicode to MARC-8. Libraries should advise LTI as to which character encoding format is being used so that profile options are properly set.

Data verification checks are made during and immediately after the transfer of records to LTI's computers to ensure that records are properly formatted in the USMARC communications format. Checks are also made to ensure that the record directories only contain numbers, that controlled heading fields do not contain non-MARC characters, etc.

Non-Filing Indicators

Setting of non-filing indicators in eight title fields is one of several pre-authority control processing operations. Non-filing indicators specify the number of initial characters to be ignored during computer filing.

For the title field (tag 245), the only title field to which the language code generally applies, articles associated with the fixed field language code are compared against the initial text in the title field. Based on this comparison, the non-filing indicator is set to 0, if no match is made, or to its proper matched value. The program takes into account diacritics and special characters associated with an article, but preceding the first actual filing character.

If the fixed field language code in bytes 35-37 of the 008 is either blank or does not match a language code, the algorithm compares the title (245) field's initial text against a table of common articles, composed from any languages, and sets the non-filing indicator to its proper value or to 0 as appropriate.

Because title fields other than 245 (e.g., X30, 240) do not necessarily correspond with the fixed field language code, LTI's program compares non-245 field initial text against the table of common articles and sets the non-filing indicator to its proper value or to 0 as appropriate.

In RDA, catalogers are instructed to include initial articles in access points. However, LC/PCC practice is to apply the alternative instructions and omit initial articles in the formulation of headings. LC authority records do not contain non-filing indicators in 1XX fields, e.g., the geographic heading is "Dalles (Or.)"—not "The Dalles (Or.)" (n 82036146). LTI follows LC/PCC practice.

Automated non-filing indicator fix programs are sometimes unable to distinguish correctly between when a leading letter (e.g., A) or word (e.g., Lo) in a title is used as an article and when it is used as another part of speech that should not be ignored in filing. LTI's software uses, when appropriate, up to four words in the title to help determine if the initial word is actually used as an article. Examples of where the non-filing indicator is set to 0 based on an analysis of the second word of the title are listed below:

A is for apple
El Salvador 1932
A la orilla del viento
Das ist mir lieb
Un de Baumugnes, etc.

While it is still theoretically possible for a filing indicator set correctly in the source record to be re-set to an incorrect value, the chances of that happening are extremely remote.

For those that insist on preserving their original non-filing indicators in the 245 title field, LTI can preserve them on request. This is not an option in controlled title fields where the removal of initial articles is controlled by explicit LC authorized headings.

LTI creates an ASCII text report showing every change made to a title non-filing indicator. This report shows the before and after settings along with the relevant title text. For libraries profiled to correct non-filing indicators, the report provides reassurance that its non-filing indicators are being correctly set. It is just as useful for libraries that have chosen not to have LTI set their non-filing indicators because it lists the changes that should have been made had the library opted to have them fixed.

Optionally, the first indicator in the 245 field can be set based on the presence or absence of a 1XX field. In other words, the first indicator is checked and if necessary changed to 0 when there is no 1XX field present in the record, or to 1 if there is a 1XX field.

AuthPrep and MARC Update Processing

Authority control at LTI begins with a generalized database clean-up program, AuthPrep, whose purpose is to increase both the probability of catalog record heading matches against authority headings and to upgrade unauthorized headings to current forms.

AuthPrep normalizes headings to correct for a variety of typographical and punctuation errors. These include elimination of leading and trailing blank spaces, compression of multiple blank spaces to a single space in 1XX/4XX/6XX/7XX/8XX fields, and deletion of blank spaces on either side of subfield codes.

AuthPrep makes many types of changes to headings, some of which correct the omission or improper assignment of content designators while others correct punctuation or bring headings into compliance with RDA. Examples of changes at the subfield code level include additions (such as inserting, where appropriate, $f, $l, $s, and $k in title fields, $c and $d in personal names, $b in corporate names, and $v in series); conversions (such as changing $b to $n in conference names, correcting errors caused by the omission or improper assignment of $c, $d, and $e in personal names); and deletions (optional removal of subfield $4 from name headings).

Complex Bible, music, and other uniform title headings are parsed and updated to conform with current cataloging rules. Leading non-filing articles are removed from uniform titles and title portions of author/title headings and unnecessary parentheses and brackets are deleted from name headings. If the library is still using GMDs in controlled title fields, and they are not surrounded by brackets, the brackets are added. AuthPrep even updates certain non-controlled heading fields -- e.g., the OCLC control number preface is changed from ocl7 to ocm0, 301/ 305 fields are retagged as 300.

Obsolete subject subdivisions such as Addresses, essays, and lectures and Collected works are eliminated. As part of this preliminary clean-up the letters l and O are converted to 1 and 0 respectively in date subfields, and a check is made to ensure that subfield code $d precedes dates in personal names. All 1XX second indicators are set to blank.

To achieve consistency with the current MARC standards, catalog records are updated to reflect the latest MARC 21 Format for Bibliographic Data tagging and coding conventions. LTI's MARC Update service is an important clean-up step for records created prior to 1987. An exhaustive table of authority control pre-processing fixes is found in the document LTI MARC Update Changes.

Changes include deletion of obsolete fields and subfields; conversion of obsolete tags, indicators, and subfields to current usage; and conversion of outdated fixed-field element codes. Examples of MARC Update changes are deletion of 039 fields, conversion of subfields $d and $e in 245, 246, and 247 fields of the serials format to the currently defined codes $n and $p, conversion of the obsolete 705 and 715 fields to 700 and 710 respectively. Several MARC Update options are offered, including deletion of LC Children's, Sears, genre headings, or NLM MeSH subject headings. Unless instructed otherwise, LTI deletes the obsolete OCLC-generated 87X fields.

Other Pre-processing Routines

Changes to cataloging rules due to RDA require special processing of series, conference names, and titles prior to authority record linkage.

Series statements (400/410/411/440) are retagged as 490 fields and assigned a first indicator of 1. An RDA series entry is then added in the appropriate 800/810/811/830 field. Removal of initial articles, capitalization changes, and adjustment of filing indicators is frequently necessary as part of this processing. To illustrate, the traced title series:

440 4$aThe series in computer science
is retagged
490 1 $aThe series in computer science

and an RDA series field is added to the record using the LC/PCC alternative to eliminate initial articles
830 0$aSeries in computer science

If the original 4XX series begins with the pronoun His, Hers, Its, or Their, the pronoun is replaced in the 8XX field with the full heading from the catalog record's 1XX field. In addition, 840 series fields are tagged as 830 fields.

In conference name headings, the order and punctuation of data elements in subfields $b, $c, $d, and $n are changed to conform to RDA. In the 111/611/711/811 fields, the obsolete subfield $b is converted to subfield $n and the number, place, and date are reformulated in parentheses with proper subfield coding and punctuation. To illustrate, the conference heading:

111 20$aInternational Conference on Elizabethan Theatre, $b1st, $cUniversity of Waterloo, $d1969
is converted to:
111 2 $aInternational Conference on Elizabethan Theatre $n(1st :$d1969 :$cUniversity of Waterloo)

Controlled title fields are checked for proper punctuation and subfield coding. Omitted subfield coding, including subfield $l before languages and $f before dates, is inserted. If the library is still using $h to designate content type, appropriate corrections will be made.

Extraction of Controlled Headings

Following AuthPrep processing, headings eligible for authority control are extracted from bibliographic records and a unique, sequentially assigned number is added to the end of controlled heading fields. This number provides a link to permit reinsertion of the authority controlled heading into the bibliographic record later in the processing cycle.

Table I lists MARC record fields and subfields checked by LTI's authority service. With the exception of subfields $u, $w, $4, $5, $6, and $9, all subfields in bibliographic record headings are matched against all appropriate subfields in LC authority record headings. Subfield $v in 8XX fields are validated and corrected wherever possible, e.g., when volume designation information has been miscoded as part of $a or miscoded as $n or $p, or when other clear errors in formatting occur. In addition, subfield $v data is corrected based on the 642 field of the referenced authority record. For LC subject authority control, only subject fields (6XX) with a second indicator of 0 (i.e., LC subject headings) are validated. A blank second indicator is treated as if it were 0. LTI offers optional authority control of LC Children's subjects, NLM's MeSH subject headings, and some genre headings.

  100 $a q b c d e k t n p l f g
  110 $a b e n d c k t p l f g j
  111 $a q e g k t p l f j
  130 $a t n p l f k s g d m o r h
  240 $a n p l f k s g d m o r h
* 400 $a q b c d k t n p l f g v
* 410 $a b n d c k t p l f g v
* 411 $a q e g k t p l f v
* 440 $a n p v
  490 1st ind. 0 - optional
  600 $a q b c d k t n p l f m o r s h g v x y z
  610 $a b n d c k t p l f m o r s h g v x y z
  611 $a q e g k t p l f s h v x y z
  630 $a t n p l f k s g d m o r h v x y z
  650 $a b v x y z
  651 $a v x y z
  655 $a 2
  700 $a q b c d e k t n p l f m o r s h g
  710 $a b e n d c t p l f m o r s h g j
  711 $a q e g k t p l f s h j
  730 $a t n p l f k s g d m o r h
  800 $a q b c d k t n p l f m o r s h g v
  810 $a b n d c k t p l f m o r s h g v
  811 $a q e g k t p l f s h v
  830 $a t n p l f k s g d m o r h v
  840 $a h v 
* converted to corresponding 8XX

Table I. MARC fields and subfields validated by LTI's authority control service

Authority Record Matching

After preliminary processing is completed, compressed "match keys" from catalog record headings are compared against an index of match keys extracted from 1XX/4XX fields in LC and LTI authority records. Links to LC authority records take precedence over links to LTI authority records.

To increase authority record links, certain tag variations in catalog record headings are ignored during match key comparisons. For example, if a corporate name (110/610/710/810 field) has been improperly tagged as a personal name (100/600/700/800 field), the link will not only be made with the proper form of the heading, but the incorrect tag will be corrected automatically.

Some headings do not link because of incorrect subfield coding, as when a chronological subdivision ($y) is miscoded as a topical subdivision ($x) and vice versa. LTI scans for and corrects such problems.

A common reason headings fail to match an authority record is because a Library of Congress authority record does not exist for the heading. Name authority records date back only to 1977 and subject authority records are a reflection of LCSH rather than an exhaustive file of subjects and subject subdivisions appearing in MARC records. Almost no name headings and only a fraction of the thousands of topical, form, chronological, and geographic subdivision headings receive their own LC subject authority records.

Other initial linkage failures are caused by typographical errors, headings constructed under earlier cataloging rules, variant treatment of names with prefixes, and direct versus indirect division of geographic names. Most of these headings are corrected and linked to an authorized heading. To achieve these links, catalog record headings are submitted to repeated manipulations and checks by computer.

Name Authority Matching

Initially, many personal name headings (100/600/700/800) fail to link with an authority heading because of variations in the fullness of birth and death dates or variations in "titles and other words associated with the name" (subfield $c) information. Tests are applied to personal, corporate, and conference name headings that disregard minor variations to maximize authority record links. For example, when the match key created for the personal name heading Allingham, Helen Paterson, $c"Mrs.William Allingham,"$d1848- fails to link with an authority record, the heading is checked without subfield $c data. If the heading still does not link, another match is tried which accepts any death date in $d, if the birth date matches. This second match key refinement allows a valid link with the LC authority heading Allingham, Helen Paterson, $d1848-1926.

When a link is found to an authority record, the form in the authority record replaces the form in the incoming heading. For many years, libraries that deviated from Library of Congress practice and added known death dates to headings for famous people had either to accept the replacement with an open date or to perform ongoing local maintenance to such headings. With the adoption of LCRI 22.17, authority records for several hundred well-known names had death dates added in a project that spanned most of 2006, with new additions weekly. Libraries no longer have to re-edit authorized bibliographic records to add this information, nor be concerned with the loss of this data in the first place.

Title Authority Matching

Title portions of name/title headings (x00/x10/x11 fields containing $t or $k) and uniform title fields (130/240/630/730/830) undergo special treatment to increase matches. In each case the title portion of the field is checked for "floating" elements which are corrected and validated separately. These include dates ($f), languages ($l), medium designator ($h), and versions ($s). Music headings also have the arrangement statement ($o), key ($r), and medium of performance ($m) corrected and validated.

Special Series Processing

While untraced series (i.e., those tagged as 490 with a first indicator of '0') have generally been excluded from standard authority control processing, LC's decision effective June 1, 2006 to discontinue providing controlled access to series in bibliographic records and to cease creation of series authority records makes it important that libraries have a mechanism to continue to treat series as controlled headings. The number of series authority records has grown less rapidly since LC ceased to create them. However, the backfile of existing LC series authority records, as well as new national-level records being created by NACO libraries, continues to be available for authorization of series headings. Over the years LTI has also created many series authority records in-house, used to match incoming headings in the absence of a national-level record.

Libraries are encouraged to take advantage of LTI's no-charge "untraced series" option that allows for the authorization of 490 0 fields. Using this option, if the first indicator in a 490 field is set to '0', LTI changes the indicator value to '1' and generates an appropriate 8XX (traced series) field. If the newly created 8XX field is linked to an authorized heading during authority control, both the 490 1 and authorized 8XX fields are retained.

If the LTI-created 8XX field remains unlinked following authority control, libraries can opt to either: (1) delete the LTI-created 8XX field and change the 490 first indicator back to '0'; or, (2) retain the 490 (traced differently) series with a first indicator of '1' and the LTI-created (but unlinked) 8XX series heading. When the form in the 8XX field cannot be matched to an authority record, LTI recommends that the 490 1 / 8XX combination be retained. Should an authority record later be distributed, it will be provided to the library when the heading is authorized during a continuing [AEX or AUP] authority control run. For libraries retaining the 490 1 / 830 series, we further advise that 490 1 fields not be indexed. The same advice would apply to 490 0 fields but, under this option, none of these fields will remain in the database.

Given the 2008 MARBI decision to make the 440 field obsolete and to use instead a 490/8XX combination, LTI also suggests that libraries no longer restore unchanged 830 fields back to 440. The decision to no longer use 440 as a traced title series clarifies the line between transcription and access points. It also redefines the 490 first indicator value '1' to "Series traced in 8XX field." Libraries using LTI's AUP service can easily convert all obsolete 440 fields to the new usage style.

Subject Authority Matching

All subject headings are first processed through a "subject fix" program that corrects common errors in subject headings and fixes incorrect and obsolete topical, chronological, and geographic subdivisions.

Using tables of commonly occurring names, jurisdictions, subjects, and subject subdivisions, abbreviations are expanded and subjects and subject subdivisions are modernized. For example:

Gt. Brit. becomes Great Britain.

Women, British becomes Women$zGreat Britain.

U.S.$xRace question becomes United States$xRace relations.

The West$xBiog. becomes West (U.S.)$xBiography.

Headings are then matched against the LC subject authority file. Because most subject subdivisions are not represented as separate LC authority records, LTI maintains tables of "free floating" topical, form, chronological, and geographic subject subdivisions.

Pattern headings in these tables are used to validate thousands of headings that would otherwise not link. Headings that have not fully linked are broken into their component parts and tested against subject authority records and tables of validated floats.

Unlinked personal, corporate, conference, or geographic name (600/610/611/651 fields) headings are checked against the LC name authority file (ignoring subfields $v, $x, $y, and $z) to validate the form of name wherever possible. Later, subfields $v, $x, $y, and $z are validated against float tables. Where libraries have used double dashes, in place of appropriate subject subdivision coding, LTI's software recognizes the subdivision and inserts the proper subfield code.

Geographic Subdivisions

LTI maintains a file of 170,000 correct indirect geographic subdivision forms. In addition, software is used to convert direct geographic subject subdivisions into indirect form. Geographic subject subdivisions are identified and fixed even when $z data has been improperly coded as $x or $y or appended to $a. Where necessary, higher level jurisdictions are inserted. For example, the topical subject heading:

650 0$aDrawing, Paris$xCatalogs.

is changed to

650 0$aDrawing$zFrance$zParis$vCatalogs.

and the heading:

650 0$aGermans in Waterloo Co., Ontario.

is changed to

650 0$aGermans$zOntario$zWaterloo County.

Through limited review processing, LTI is presently linking on average between 96% and 99% of subject headings for academic and public library databases.

Split Headings

Obsolete LC headings replaced by two or more valid headings (i.e., "split" headings) present special authority control problems. For example, the topical heading Negroes was replaced by the headings Blacks and Afro-Americans; then, in 2001, Afro-Americans was changed to African Americans. In some cases the correct division of split headings can be deduced from other parts of the heading. Thus, LTI automatically converts headings having the structure Negroes$z[State] to African Americans$z[State], e.g., the heading Negroes$zMississippi is changed to African Americans$zMississippi. The heading Negroes followed by a country other than United States is changed to Blacks.

Where there is insufficient information to make the split, LTI links all occurrences of the obsolete heading to the broader heading. For example, Crime and criminals will go to Crime. However, if Crime and criminals were followed by a Biography subdivision, the new heading would be changed to Criminals. LTI's handling of splits is not affected by whether the job is limited or full review.

Form Subdivisions

In early 1999 the Library of Congress began to issue authority records with form subdivisions in $v, heretofore coded $x. LTI analyzed LC's form subdivision usage patterns and created processing guidelines for the assignment of $v. Briefly, when a heading contains a subdivision that is valid for use as a form subdivision and it is the last subdivision in the heading, it will be coded as $v, except in certain special cases, e.g., when there is a full link to an LC authority record containing the subdivision in $x. Conversely, if the subdivision can be $v, but is not the last subfield in the heading, it will not be changed to $v. Exceptions to the latter rule are if it has been identified as a special case which will take a $x following a $v, e.g., $vDictionaries$x[language] or when it is permissible to follow $v with another $v.

Role of Added Cross-References

An important component to LTI's ability to offer a guaranteed link rate is a supplemental file of 4.5 million added cross-references. Name headings constitute 88% of the cross-references; the remaining 12% are subject cross-references. Each reference refers from the form of the heading used in the catalog record to the correct form used in the LC authority record.

These references are not added to LC authority records, but rather cumulated in separate files that are processed after linking to LC authority records, but before linking to LTI authority records. For example, when an LTI editor links manually the library heading Marquand, John P., $d1893- to the LC authority record heading Marquand, John P.$q(John Phillips),$d1893-1960, that cross-reference is saved and applied subsequently to other library databases. Because not all cross-references can be applied to every database, editor-created cross-references undergo a second review prior to being added to LTI's cross-reference file.

Added cross-references serve two purposes. First, they correct the heading in the library database that prompted their creation. Second, when the same unlinked heading appears in another customer's database, that heading is automatically linked to the proper authority record, thereby reducing the number of headings that require manual review and allowing LTI to focus on the research and establishment of headings that are genuinely new. Because so many machine-readable records are derived from shared cataloging databases, these supplemental cross-references play an important part in LTI's authority control routines.

When the complete catalog record heading cannot be validated or linked to an authority record, an attempt is made to link portions of the heading. Through limited review processing, LTI is presently linking 90% to 96% of name, title, and series headings, either fully or partially to a nationally distributed authority record, for most academic and public library databases.

LTI Authority Record Linking

LTI maintains its own file of name and subject authority record headings established in accord with RDA and LC cataloging practice. Presently, there are 2.4 million LTI authority records. These authority records are created from validated but unlinked headings that have appeared in library databases. To qualify as an LTI authority record heading, the heading must meet three criteria:

  1. it has been searched thoroughly but not found in the LC authority files
  2. it is coded properly (tags, indicators, and subfield codes)
  3. it conforms to national cataloging standards

If an LC authority record is later distributed for the heading, the LTI authority record is deleted. Library headings are matched against LTI authority record headings only after they have failed to link to an LC authority record heading. In a typical database, LTI authority records validate 3% to 4% of the headings and most of these represent no change to the source heading-i.e., the heading in the library's catalog record is identical to the LTI authority record heading.

A few years ago an analysis of a one million record client database showed that 3.2% of the controlled headings were validated against LTI authority records. Six out of seven of these headings were not changed by LTI-i.e., the headings appeared in the authorized catalog records exactly as they appeared in the library's source records. Where changes did occur, in 1,300 [0.0003%] out of 4.4 million headings, the variations were primarily attributed to content designation fixes and minor differences in the headings. This includes insertion of $d (date) and $q (fullness of name) in personal names, $b in corporate names, and correction of tagging errors in subjects. Again, the sole purpose of LTI authority records is not, in the absence of a nationally distributed authority record, to change a library's headings; but rather to reduce the number of unlinked library headings that need to be reviewed by LTI editors. By eliminating headings that have already been reviewed in a prior job, editors are able to focus more attention on the unlinked headings that can most benefit from manual review. Libraries that plan to examine the unlinked headings report also benefit from exclusion of these valid headings from that report.

Review of Unlinked Headings

After all possible machine matches have been made, LTI editors selectively search targeted unlinked headings in the LC name and/or subject authority file. Sometimes an editor needs to view the bibliographic record(s) from which headings were extracted to determine if they represent the same person or entity. Editors have access to a fully indexed version of the library's database and can display catalog records to resolve ambiguous headings.

Incorrect tags and subfield codes, typographical errors, omitted or incorrect dates, and related problems are corrected manually and resubmitted for relinking. Where the same heading is linked to obviously different bodies, as sometimes occurs with acronyms, the editors temporarily force the correct link for that specific database.

Authority Record Distribution

Most libraries request files containing LC authority records that have linked to the library's database during processing. Authority records prepared by LTI are written in accord with the MARC 21 Format for Authority Data. Bibliographic records are returned to the library in the same format they were received. At this time LTI returns LC authority records only in MARC-8.

Separate authority records are extracted for each level of a multi-level heading. For example, three authority records would be extracted from the heading:

English poetry$yOld English, ca. 450-1100$xHistory and criticism.

English poetry
English poetry$yOld English, ca. 450-1100
English poetry$yOld English, ca. 450-1100$xHistory and criticism.

For databases up to 250,000 records, the library can expect to receive about one LC authority record (name or subject) per bibliographic record. The ratio of linked LC authority records to bibliographic records is inversely proportional to database size. For example, in a database of one-half million records the ratio is close to .65-i.e., .65 X 500,000 = 325,000 authority records. Above two million bibliographic records, the ratio stabilizes at about one authority record per two bibliographic records. Linked LC authority records are deduped so that the same record appears only once. LC name authority records are written to a different file than subject authority records. Name authority files contain only LC name authority records. Depending on the library's local system, subject authority files contain both topical and geographic subjects, as well as name authority records for names and uniform titles that have been used as subjects. About 30% of a library's subject authority records are likely to be LC name authority records that have been used as subjects (600/610/611/630 fields).

The default option is for a library to receive all LC authority records referenced in its bibliographic records. Upon request, libraries may instruct LTI to return only those authority records that contain a see (4XX field) or see also (5XX field) reference. About two-thirds of LC authority records contain a cross-reference.

In May 2007 LC announced its intention to begin creating and distributing "Subject Authority Records for Validation Purposes." Presently, the number of these records has plateaued at about 79,000. The reasoning behind the project was to reduce the cost of subject cataloging by providing more subject string authority records for popular and frequently-assigned headings. Presumably, they would also make it easier for local systems to validate LCSH subjects. To date these authority records are limited to: (a) 651 subject heading fields for country names followed by free-floating subdivisions; and, (b) subdivisions found in Free-floating Subdivisions: an Alphabetical Index that appear after topical and geographic headings. They are barebones records containing no references and identifiable by the presence of a 667 field [nonpublic general note] that carries the text "Record generated for validation purposes." While this type of authority record may be useful in an ILS that requires an authority record for every controlled heading or for libraries that lack a comprehensive authority service such as AEX or AUP, some LTI clients have asked that they be excluded from their subject-related authority records. As their number grows and their value is questionable to some, LTI has responded by adding an option to not return subject authority records containing a 667 field with the validation purposes note.

Similarly, because a number of libraries have reported problems with the display of non-roman 4XX fields within their local systems, a profile option exists for AEX and AUP users to elect to receive updated authority records without the 4XX references in non-Latin scripts. LC began distribution of these records in mid-2008; there are now over one-half million of them.

"Deblinding" Authority Records

LC authority records are structured so see references never point to a heading that is not found in the library's database. In other words, see references are already deblinded and do not require further processing on the part of the authority control vendor.

Deblinding can also refer to the removal of certain see also references. Deblinding at this level prevents the occurrence of see also references when the see also from headings are not present in the catalog. For example, deblinding would prevent the see also reference Baked products see also Bread when there are no records with the heading Baked products but there are records with the heading Bread. LTI recommends that such references be retained since the see also information may be helpful to patrons even when the see also from heading is not currently used in a catalog record.

The following summarizes a posting to the LTI Users List and makes an excellent point. "Blind references" in an online catalog do not result in wild-goose chases in the same way they might have in card catalogs. Take, for example, the reference "Ho, Ho see He, He". In a card catalog the user would have to flip through cards to find out what, if anything, was filed under "He, He." Some references would involve opening new drawers, and depending on the size of the catalog, covering a bit of ground. However, many online catalogs tell one right away what to expect, e.g., Ho, Ho see He, He (0 records). Even if the number of records does not display up-front, the correct form should only be a click away. Informing users what the authoritative heading is, and that there is nothing there, actually prevents wild-goose chases. This is especially true of subject headings, with their sometimes counter-intuitive forms.

LTI Authority Reports

At the conclusion of an authority control job, libraries receive summary statistics showing authority record link rates for name, series, and subject headings. LTI's Final Link Report details the number and percentage of name, series, and subject headings that have linked fully, linked partially, or not linked to either an LC or LTI authority record. Included in the report is a table showing the frequency of each controlled heading field, the number and percentage of headings both validated and not validated against an LC authority record, and the number and percentage of headings changed following the final link procedure.

Every authority control job, be it batch or ongoing, generates an ASCII text file of unlinked headings. These files can be loaded into a word processor for review purposes. In reviewing the unlinked heading reports, one should keep in mind that in the vast majority of cases, the only thing "wrong" with these headings is that no LC or LTI authority record exists for the heading. Most clients do not systematically search unlinked headings in nationally distributed authority files.

880 Field Data

While LTI does not authorize alternate graphic representation data in 880 fields, there are two reports available for batch and continuing authority control services that make it easier for libraries to update 880 field data. These reports are produced at no charge but they must be specifically requested by the library.

The first lists controlled headings with $6 that were changed during authorization. Each change is shown when it happens but not repeated in subsequent processing-i.e., continuing authority control service reports. This ASCII text report may be reviewed by library staff to make needed edits to the corresponding 880 fields. Format of data shown on the changed report includes the bibliographic record control number, the tag and content of the controlled heading field before updating, tag and content of the revised field after updating, and the content of the linked 880 field that may require local revision. Note that the original data is displayed as raw ASCII.

A second report lists errors in 880 fields, such as bad parsing of $6 data or the field linked to the 880 is not present in the catalog record. For AUP users receiving changed bibliographic records this report continues to list errors until they no longer exist in the copy of the database maintained at LTI-i.e., unless the "base file" is replaced, even if the library makes the needed corrections locally. Format of data includes the bibliographic record control number, the tag and content of the controlled heading field with $6, the tag and content of the linked 880 field (again raw ASCII), and a brief explanation of the error found.

MeSH, LC Children's, Sears & Genre/Form Headings

LTI's approach to NLM MeSH, LC Children's, and Genre/Form heading authority control parallels procedures for LCSH headings. Separate files of authorized headings are maintained for each controlled vocabulary.

NLM MeSH Headings

Using the National Library of Medicine's MeSH authorities file, LTI offers a MeSH authority control service to medical and health sciences libraries. NLM headings are updated annually. Topical (650) and a few geographical (651) subject headings having a second indicator of '2' are eligible for MeSH processing. Major and minor descriptors, as well as subheadings, are included in the MeSH file. Conversion of MeSH to LCSH is not an option.

LC Children's Subject Headings

In 1996 LC started distribution of Children's authority records based on Library of Congress usage. Because LC Children's headings can contain adult headings considered appropriate for children's use, LC Children's headings are first matched against LC's file of Children's authority records, and then against standard LC subject and name authority files.

Given that conflicts do occur between LCSH and LC Children's headings (e.g., LCSH Swine versus the LC Children's Pigs), libraries may want to consult with their ILS vendor about the desirability of integrating the two controlled vocabularies in a single index.

LTI offers four options for processing LC Children's headings:

  1. Authorize them as LC Children's headings using LC's (sj control number) Children's authority records
  2. Convert them to LCSH
  3. Delete them from the library's bibliographic records
  4. Ignore them completely during processing

When Children's headings are to be converted to LCSH, during a pre-processing routine, second indicator codes of '1' in 6XX fields are changed globally to '0' and the subject subdivisions Juvenile literature, Juvenile fiction, etc. are added to the converted heading. Following authority control, resulting duplicate headings are removed from records. For example, assume the library's source catalog record has the following two subject headings:

650 0 $aFishes$vJuvenile literature.
650 1 $aFishes.

Following authority control two identical LCSH headings will exist--i.e., $aFishes$vJuvenile literature. One of these headings will be deleted because a final LTI check eliminates controlled headings that are truly identical after authority control.

Children's headings having no LCSH equivalent--e.g., French language materials--are retained, though the second indicator is still set to 0.

Sears Subject Headings

The following options are available for Sears heading processing:

  1. Convert them to LCSH
  2. Delete them from the library's bibliographic records
  3. Ignore them completely during processing

Genre/Form Heading Processing

Genre headings in 655 fields are authorized using LTI's Genre Heading processing option. Several types of headings may be included: Library of Congress, NLM MeSH, and GSAFD (based on Guidelines on Subject Access to Individual Works of Fiction, Drama, Etc.). LTI may authorize additional genre/form controlled vocabularies in the future when demand and authority record availability warrant it.

A number of authorization options are available. GSAFD headings (tagged 655 _7 …$2gsafd) may be authorized using that list. As the complete file of GSAFD authority records is available for free download on the Internet, no individual authority records are provided by LTI. At the library’s option, GSAFD headings may also be converted to the Library of Congress equivalent.

LC Genre/Form headings have taken several forms in the relatively short time since implementation. Initially, LC’s approach was to take from LCSH those headings that described forms or genres, using them in the field, tagged: 655 _7 … $2lcsh. Later, to emulate subject heading use, this was revised to prefer: 655 _0, with no $2. In June 2010, LC announced that it would, instead, create a new thesaurus for genres and forms, to be called Library of Congress Genre/Form Terms for Library and Archival Materials (LCGFT). Headings taken from this list are assigned as: 655 _7 … $2lcgft. In May 2011 LC completely replaced the form/genre authority records using the control number prefix “sh” with the “gf” authority records.

In authority control processing, 655 headings with (fields tagged in any of the above forms) are pulled from bibliographic records for processing and compared against LC's genre/form (gf) authority records and LTI-created authority records derived from official and semi-official sources. Content of the headings is updated to current usage, including correction of typographical errors in entry. If the subfield coding is absent, headings will still be pulled if the code is present following a space, e.g. $aHistorical fiction gsafd will be pulled and $2 inserted to create $aHistorical fiction$gsafd. Typos in the codes are also corrected: $2lcgtf is corrected to $2lcgft. To comply with current usage, all LC-derived headings are converted to 655 _7 …$2lcgft.

Prior to the implementation of genre/form headings, many libraries assigned the corresponding terms in LCSH as topical subject headings. LTI offers an additional option to convert such headings to 655 fields containing the current LCGFT term. The latter conversion occurs only with stand-alone $a genre/form headings. If an LCSH topical heading includes another subfield─such as $v, $x, $y, or $z─the heading is not considered a form heading. When returned to libraries, genre/form authority records are placed in a separate file; they are not included with subject-related authority records.


Processing time for limited review authority control is three weeks for databases containing 300,000 or fewer bibliographic records, four weeks for databases up to 800,000 records, and five weeks for databases of one million records. Scheduling for databases larger than one million records will be provided on request.

For scheduling purposes, the processing time for a job "starts" after two events occur: 1) 1) LTI receives a readable version of all the customer’s machine-readable records in MARC format; and,; and, 2) 2) LTI receives a completed Authority Control Work Specification Profile (WSP). The WSP should be completed and submitted online. Authority control options designated by the customer in the WSP, along with any attachments describing special instructions, becomes the official document describing what processing is to be performed. The WSP takes precedence over telephone and email communications.

While Your Records Are Being Authorized

During the period in which the library's bibliographic records are being authorized, staff should understand that no changes are to be made to catalog records. This is not the time to enhance records by adding local notes, secondary added entries, subjects, etc. When the post-processed bibliographic records are returned after authorization, any changes made to records will be lost as part of the "overlay" process. Also, this is not the time to conduct a "weeding" project--that should be done in advance of when the records are exported.

There is no need for libraries to export item records as item fields (e.g., 949 fields) when the only database service needed is authority control. This means that, while bibliographic record data is "frozen" during the time in which the records are being authorized, the library may continue to make changes to item records. For example, library staff can make changes to call numbers, location codes, barcode numbers, copy and volume information, or any other data contained in the item records. Based on the bibliographic record's local system control number, item records are going to be re-linked to catalog records when the authorized bibliographic records are loaded back into the database following authorization.

It follows that a library can continue to create new item records, as well as delete existing item records, while its bibliographic records are being authorized. Similarly, a library can continue to add new bibliographic records, along with associated item records, while the database is processed through authority control. The library will want to keep track of the date its bibliographic records were exported so that catalog records added after that date can be extracted for whatever continuing authority control service the library may wish to use.

There are certain situations when it is necessary for a library to export item records (i.e., formatted as item fields) along with its bibliographic records. The most common reason is that the library is migrating to another local system and it will be necessary to re-build the item fields as item records within the new local system. Occasionally a library will want to dedupe and authorize its bibliographic records at the same time. In this case item fields must reside in the exported bibliographic records or else item records will be "orphaned" when the bibliographic records are reloaded. Deduping a "live" database poses special problems and should only be done following close coordination between the library's local system vendor and the database vendor.


LTI recommends that libraries use their ILS vendor's utility program to convert exported records to MARC-8 before sending files for authorization. However, we do offer an option to work directly with Unicode [UTF-8] encoded catalog records. At this time LTI returns LC authority records only in MARC-8. Internally, prior to matching headings against LC authority records, we first convert controlled headings from Unicode to MARC-8. Libraries planning to submit Unicode records should so advise LTI so that profile options are properly set.


On March 31, 2013, LC and other national libraries officially adopted RDA rules for all new cataloging. The Program for Cooperative Cataloging (PCC) Policy Committee "Day One" for RDA Authority Records was March 31, 2013 as well. As of that date, only RDA authority records are permitted to enter the LC/NACO Authority File. Similarly, all access points in bibliographic records coded "pcc" must now be created under RDA rules. This applies even if the bibliographic description follows AACR2. Presently, no date has been announced when PCC institutions will be required to contribute RDA bibliographic records, although some libraries are already doing so.

The implementation of RDA-based authority control was handled in two phases by the Library of Congress (LC). In Phase 1, records that are not suitable for RDA use were flagged with a 667 field stating that the 1XX field cannot be used under RDA until the record has been reviewed and/or updated. These records include pre-AACR2 and AACR2 compatible records, as well as AACR2 records containing elements not compatible with RDA or that require evaluation. These headings will be upgraded over time by LC and NACO participants.

Phase 2 occurred during the first quarter of 2013. At that time, automated revisions were made to all appropriate authority records, the records were coded as RDA and re-distributed. By March 31, 350,000 records were redistributed.

LTI's Role

LTI's goal is to assist libraries in making the transition from AACR2- to RDA-based authority control as easily and quickly as possible. Effective January 15, 2013, all LTI clients began to receive authority records created with both AACR2 and RDA cataloging rules. Consequently, controlled headings in bibliographic records may reflect either set of rules, based on the content of the 1xx in the linking authority record. Note that no changes in the fields used for bibliographic description will be made by LTI. Records with bibliographic descriptions that use either AACR2 or RDA may be submitted for LTI processing, as "hybrid" records (controlled headings in RDA in records created using AACR2 rules) have been deemed acceptable for use.

We anticipate library transitions from AACR2 to RDA will occur over an extended period of time. During this period LTI will make every effort to assist customers in integrating the new rules for controlled headings. We also understand that some libraries have no plans or desire to adopt RDA until well after its official use by national libraries. Those libraries may continue to create or adapt bibliographic description using AACR2 rules for their databases, while receiving the nationally approved forms of controlled headings as created under RDA rules.

Library's Role

LTI client libraries should examine their processing profiles to ensure that the options reflect their future needs. Specifically, RDA assigns $e relator terms that were formerly seldom used and customarily deleted from bibliographic headings. A profile change may be needed to retain those terms. Libraries should also determine if inclusion in the special RDA/AUP run is useful and notify LTI of that decision. If there are questions about the advisability of being included, please contact LTI to discuss the best options.

RFP's and Tests

Authority control projects sometimes involve a Request for Proposal (RFP), Request for Quotation (RFQ), Request for Information (RFI), etc. While, on occasion, this is a legal or administrative requirement, creation of an RFP by the library, as well as the vendor's response to it, are both time-consuming and expensive to all parties. Libraries tend to "borrow" heavily from other library RFPs or a suggested set of specifications prepared by a particular authority control vendor. RFPs sometimes include specifications that are no longer current, or adopt a pre-ordained approach which, while offered by another vendor, may be less effective than their competitors’.

We advise those libraries that must use an RFP approach to exercise caution in adopting authorization specifications that have been lifted from an authority vendor’s model RFP. Incorporating vendor-created boilerplate into the library’s specifications may seem innocuous but it interferes with evaluation of genuinely important specifications.

For example, a requirement to provide a report listing headings that match two or more authorized headings makes a presumption that such a report is useful, which, in turn, relates to how an authority control provider goes about its work. From LTI’s perspective, by definition “two or more authorized headings” for the same unique heading cannot exist. Following authority control, a heading is either linked to an authority record or it is not linked. The nature of authority records is that no heading can link to two identical authorized headings. “Multiple match” reports are composed of headings which link to several identical cross-references. The bibliographic heading may be represented by one of these authority records or may represent a different entity entirely. If staff are examining unlinked headings based on a list, no time is to be saved by indicating that there are two or more possibilities, especially since none is necessarily correct.

Some RFPs require a vendor to provide numerous reports upon completion of authority work. However, unless a report presents summary data, its very existence implies that someone on the library’s staff is going to have to review the information, either as a requirement to fix ambiguous or unlinked headings, or because the library believes it necessary to quality check the vendor’s processing. Regardless, library staff are being asked to do work which the institution contracted with the authority vendor to do. Authority control processing quality is not improved by the effort required of staff to clean up the database from reports, but from sophisticated processing on the part of the authority control vendor.

Similarly problematic, is accepting one set of “Highly Desirable Requirements” on the assumption that the identified requirements define the playing field. For example, LTI alone among authority vendors offers a comprehensive continuing authority control service that updates not only the new and revised authority records but one that also returns the library’s updated bibliographic records for overlay, thereby removing this time-consuming and risk-prone task from the shoulders of library staff. Unless one is aware of this unique capability, it cannot be included, thereby missing the opportunity to continue to save staff time for years into the future. Other common-sense requirements that would ensure quality, but are seldom seen in RFPs are the need for some level of editor review in backfile authorizations and rapid (under one-hour) turnaround for authorizing new cataloging records.

Test Databases?

Should a library submit a test database to several vendors and compare the results? Asking vendors to run a test on several thousand sample bibliographic records prior to selecting a vendor can be a useful tool in deciding which vendor to use. Assuming the sample records are of sufficient number and drawn randomly, and that there is a short turnaround time, such a process permits one to make meaningful comparisons of how different vendors performed.

To be able to draw useful conclusions it is important that test records be selected in a random fashion—e.g., every Nth record from the database. Once test records are extracted, staff may want to include special interest records to see how vendors handle problematic headings. Keep in mind that, up to a point, the larger the database, the larger the sample should be – asking an authority vendor to authorize a test file of one thousand bibliographic records for a library having a database of one million records does not provide useful results. It is also advisable to specify a short turnaround time for the test, to minimize the opportunity for vendors to devote extraordinary attention to the test database. Note too that the library must have the resources to analyze and evaluate the work returned from the various authority control providers.

Pre-authority control tests can be useful in other ways. They can determine if:

  1. the library is able to extract its bibliographic records in MARC format
  2. the local system ID or control number appears in every record (this will be the necessary match or overlay point when the bibliographic records are re-loaded after authority control)
  3. the library can send and receive files of bibliographic and authority records via FTP
  4. the necessary load tables are in place that will allow the library to re-load the post-processed bibliographic and authority records back into the library's local system.

Re-authorizing the Library's Database

For libraries lacking the staff or resources to maintain headings following batch authority control, exporting and re-authorizing the entire database every few years may be the only way to keep controlled headings in synch with LC.

When a database that has previously been authorized is re-submitted for authority control, there is no need to export item record data or the library's existing authority records. All the authority control vendor requires is the bibliographic records. After the re-authorization the library should be prepared to delete all its existing nationally distributed and local authority records. LC, LC Children's, LC Genre/Form, and NLM MeSH authority records are completely replaced as part of the re-authorization. Similarly, ILS software generates new provisional authority records for headings for which no nationally distributed authority record is available.

Following re-authorization, the library's catalog records are re-loaded into the local system database by "overlaying" on the ILS's record ID control number. New authority records and bibliographic records are loaded and new indexes are built.

Some libraries may not want to delete their old authority records either because they have added cross-references or notes or removed cross-references that they consider not useful for their catalog, or because they are advised by their ILS vendor to "overlay" the new authority records. At least one local system vendor encourages the retention of existing authority records by imposing a high fee to delete the library's old LC and/or local authority records. Retaining old authority records rather than starting fresh with authority records directly referenced in those bibliographic records, will result in several kinds of conflicts as described below. The list is not intended to be exhaustive. Such conflicts may be minor or major, frequent or infrequent-but they are inevitable and the library pays a price for keeping outdated and local authority records.

  1. Duplicate LC authority records--Each week LTI reports to LC duplicate authority records. These are cases where the 1XX heading is generally the same in both records, however the LCCNs of the two authority records are different. If the library's file contains the first of two duplicates and the file from LTI contains the second, two authority records will exist in the library's file. Though the authorized headings are frequently identical, there may be minor differences between the two, e.g. $d1900- compared to $db. 1900. There may also be variations in cross references.
  2. Deleted LC authority records--The library may retain in its old authority file records deleted by LC. These may be in direct conflict with the current LC file.
  3. Unlinked LC authority records--Unless the library has scrupulously deleted authority records from the file whenever the last occurrence of that heading was deleted from the bibliographic record file, the current authority file probably contains authority records for which no heading exists in the bibliographic file. The advantage of starting with a totally new authority file is the knowledge that all authority records apply to the bibliographic file.
  4. LC vs. locally created authority records--If the library created a local authority record and LC later distributed an authority record for that heading, the forms of headings in the 1XX may not agree. More serious problems arise when the heading in the library's local record matches a 4XX in the LC record.
  5. LC changes pattern heading structure--For example, several years ago LC replaced hundreds of headings of the type $aTrade unions$x[Industry]. The replacement headings were mostly of the type $aArtists $xLabor unions, but sometimes varied: $aTrade unions$x College employees became $aUniversities and colleges$x Employees$xLabor unions. In these situations, the new authority records often contain the old form as a cross-reference, resulting in a conflict.

One of the benefits of a newly authorized database of bibliographic records is the corresponding files of comprehensive and up-to-date LC authority records. Why compromise that by mixing old authority records with new ones?