Whenever I try to access the Online Catalog, I get a message that "all available connections are in use?" What does that mean? Why is it so hard to connect to the Catalog?
The Library of Congress Online Catalog has proven so popular that it is often the case that all connections are in use. We are aware how frustrating this is, and we are working with our software vendor to increase the number of simultaneous users so that no one has difficulty getting in. We expect to move gradually towards that goal over the next few months. Until we are able to expand access to the LC Online Catalog, here are some tips for users:
- Our peak usage is typically Tuesdays, Wednesdays, and Thursdays between 10:00am and 2:00pm (US Eastern Time). We suggest trying to search before or after those hours, or on Mondays, Fridays, and weekends (during off-peak hours).
- Also, please be persistent and keep trying. Users are leaving the system, and freeing up connections, at about the same rate that they are entering the system. Connections open up continually as users exit the system. If you continue to try several times in quick succession, you will move up in the queue and gain access more quickly.
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I have a slow Internet connection. Is there text-only access to the Online Catalog?
The Library is currently not able to offer TELNET access to a text-only version of the LC Online Catalog. An alternative interface is available using the Library's Z39.50 Gateway. This interface works well with text-based browsers, such as Lynx. To learn more about the Z39.50 protocol for information retrieval, visit the Z39.50 Maintenance Agency Page.
The Library is aware of the need for text-based access to the Online Catalog to satisfy the needs of its offsite users. The Library is working with its system vendor, Endeavor Information Systems, Inc., to ensure that its system is accessible via a variety of browsers.

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Searching/ Browsing the Online Catalog

I am sure the Library has the item I am searching for, but I cannot find it in the Online Catalog. What should I do?
Many items from the Library's special collections are accessible but not represented in this Online Catalog, including:
- Some individual items within collections (microforms, manuscripts, photographs, etc.) are not listed separately in the Catalog, but are represented by collection-level catalog records.
- Older materials in the general collections cataloged before 1980 may also not be in the Online Catalog. (Onsite researchers should also use the Main Card Catalog.)
See Question #17, "What other catalogs are available?"
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I've checked all those other systems in Question #4, and it still looks like the Library doesn't have what I need. Now what?
While the Library of Congress is one of the largest libraries in the world, it doesn't have everything. If it seems like the Library doesn't have what you are looking for:
- Try the Library's new "Ask a Librarian" service.
- Try your local public or college library. Most libraries have access to a number of online databases, and can locate and borrow items for their patrons through Interlibrary Loan. Your local library is often the fastest and easiest resource for locating hard-to-find items.
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Why can't I find name and subject authority records in the online catalog?
Full MARC 21 authority records (names and subjects) are not available directly from the Catalog. However, they are available through a separate service, Library of Congress Authorities, at authorities.loc.gov. For more information, see "About Library of Congress Authorities."

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How can I view numbers from the Dewey Decimal Classification (DDC) system in the LC Online Catalog?
While many Library of Congress Catalog records (mostly those for books) contain Dewey Decimal numbers, the majority do not. The Library generally assigns Dewey numbers to nearly all U.S. trade imprints, including all titles cataloged in the Cataloging in Publication (CIP) program, and to many books in English, French, German, Italian, Spanish, and Portuguese.

You can search the Catalog by Dewey number:
- by using Keyword in "Basic Search,"
- in "Guided Search" with Keyword Anywhere selected, or
- using the Command Keyword search using the index code K082.
Please see the online help screen at URL <http://catalog.loc.gov/help/ckwindex.htm#number> for more information.

Dewey numbers are not shown in the Brief Record display. They are displayed in either the Full Record or MARC Tags displays, accessed by selecting the tabs at the top of the Brief Record display.
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7How can I search for government documents by their SUDOC numbers?

To search by SUDOC number, use the Command Keyword search method with the K086 index code. For successful results, punctuation and spaces must be exactly as entered in the record, and always enclosed in quotation marks (e.g., K086 "Y 4.F 76/2:el" with a space after the Y and the F). The SUDOC is displayed in the Full Record display under the label Govt. Doc. No.:. It is also found in the MARC Tags display in field 086.

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Search Results and Output

How do I see the full text of the title I found?

The full text of the printed books in the Library's collections is NOT available in the Online Catalog.

While most of the records in the Catalog describe "physical" items in the collections (books, print periodicals, sound recordings, etc.), the Library does have a growing collection of electronic resources: digitized photographs and motion pictures, electronic journals and databases, etc.
- To identify these electronic items in the Catalog, look for the label Links: on the "Brief Record" display. These links will take you to the electronic item described by the record.
- For more information about the Library's digital collections, see Question #17, "What Other Catalogs are Available?"

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How do I download MARC records from the Online Catalog?

To save (download) MARC records from the Catalog, use your browser's "File | Save" feature. For more detailed information, see the help file on saving MARC records.

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How can I reformat records I've downloaded from the Catalog?

There are a number of thrid-party commercial software products available specifically designed to manipulate and reformat MARC21 records, such as those from the Library's Catalog. In addition to a "card" display, most of these products also allow output in a variety of other bibliography and citation styles.

A list of these products is available at:

Open Directory Project

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When I try to Email a MARC record, I get plain text catalog records. What happened?

While it may appear that it is possible to Email MARC records, it is not. While there are 4 formats currently listed in the drop-down menu in the Save, Print, Email box, only the "Text (Full Information)" can be emailed. It is possible to:

A. Print or Save records in either of the 2 "text" formats

B. Save records in all 4 formats in the drop-down menu

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When I email records containing special characters or diacritics, I notice that information is missing in my emailed record. What happened?

When emailing records containing non-Roman (unicode) characters or any diacritic marks, the email received will not contain the entire line of text with where the characters or diacritics were present. Records with no diacritic marks will be emailed in tact.

This bug has been reported to the vendor, but until it can be fixed we recommend the use of Print or Save to capture records containing non-Roman characters or diacritic marks.

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How does relevance ranking work and where is it available?
The results of a Keyword search on the "Basic Search" screen are displayed in order of their relevance to your search. In the Title List following a Keyword search, the display will include a column with a "Relevance" indicator; the most relevant items display first. The relevance is determined by three factors:
- Uniqueness of search terms within the database.
- Proximity of search terms to each other within the catalog record.
- Number of different search terms present in a catalog record.
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Why do some records have the legend "Library of Congress Holdings Information Not Available?"

This legend displays on Online Catalog records in three general categories:

-- items cataloged before they are published, through the Cataloging in Publication program. The Online Catalog does not include holdings information in these records until the Library receives the actual books.

-- records for items which were cataloged as part of a special progam but not added to the Library's collections (e.g., large print books).

-- records for which holdings and location information could not be created during the initial migration of data from legacy systems to the current Online Catalog. Plans for correcting these records are underway.

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How can I find out whether the Library of Congress has a particular issue of a journal I need?
Beginning October 1, 1999, Library staff have been checking in new serial issues as they are received, starting with a few titles and then gradually adding more until all current receipts are checked in. Retrospective conversion of the older manual files will take several years. Until all titles have been converted to the new system, researchers will still need to contact the Library to find out whether or not a specific issue is held by the Library.

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When I look at a catalog record for a newspaper, the record says the Library of Congress has a complete run. But when I try to request a particular year at the Library, I'm told that the Library doesnt have it. Why is that?
Researchers commonly misinterpret the span of dates in catalog records as holdings information. Holdings information for newspapers held by the Library is not yet available. Beginning in 2000, the Library has been adding summary holdings for every newspaper it has. Eventually, researchers will be able to know from the Online Catalog what years of a newspaper the Library has in microfilm and bound formats.

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What does the phrase [from old catalog] mean?

This phrase identifies records that were created using older cataloging rules ("PREMARC" records) and which contain obsolete and older forms of terms and headings. Out-of-date headings are being assessed and updated to conform to current cataloging practice.

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Relation to Other Online Catalogs

Where can I search the Braille and Audio catalog?

The online catalog of the National Service for the Blind and Physically Handicapped is available through a special accessible Web interface >> Search the catlog now.

Please consult the home page for the National Service for the Blind and Physically Handicapped <http://www.loc.gov/nls/> for additional information on the Book Catalogs and Listings.

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What other catalogs are available?

In addition to the main Library of Congress Online Catalog, the Library currently has a number of other catalogs for materials in its collections. Many of these are for special format materials, such as digital collections (see American Memory), prints and photographs, sound recordings, etc. Please see the Digital Collections and Programs web page for more information.

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Where can I search the Copyright files?
The U.S. Copyright Office records--including registration information and recorded documents from 1978 to the present--are available via <http://www.copyright.gov/records/>.

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Library of Congress Online Catalog - catalog.loc.gov
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October 26, 2007