The classification browser displays Library of Congress classification data with cross references to authority data, correlations to bibliographic records and links to online library catalogs. There are three versions of the classification browser with varying levels of number calculation. You also have the option of creating local application notes and hyperlinks that are displayed in-line with the classification data. These notes are displayed in red to help them to stand out.
Note: When using the Enhanced and Hierarchy browsers and a modified classification table is applied, some of the classification numbers in your display may have a yellow background. This is normal and the highlighting indicates that these are table modification records.
Access the classification browser from the main menu by clicking on the LC Classification link. This provides the ability to browse classification records using a number of different access points (most importantly, by class number). Use the search link to run keyword and multi-field searches.
The classification browser comes in three flavors which differ in the amount of information they display and the degree to which they automate the application of classification tables. Classification tables contain information that is used in more than one area of classification, including geographic names, forms of material and other subdivisions.
By default, ClassWeb uses the Enhanced Browser to display classification data. You can change the default browser for your account using the Settings link found on the drop-down menu at the top of every page (requires administrative password). This will affect all users of your account. Alternately, you can choose a browser type using the links near the bottom of the main menu.
The three classification browser types are:
The Standard Browser displays the classification schedules with links to other areas of classification and to the classification tables. When you click on a table link in the Standard browser, the data on your screen is replaced with the contents of the table. All classification number additions and calculations must be performed manually by the cataloger.
The Enhanced Browser is the suggested (and default) browser to use for classification data. It automatically merges classification table data into the main classification display. When you click on a table link in the Enhanced browser, the table is integrated into the display (including properly calculated classification numbers). Please note that to avoid cluttering the screen, the Enhanced browser will only apply a table and display its content when you click on a table link. The only time ClassWeb will automatically apply tables is when you enter a classification number into the Find... prompt at the top of the screen. In that case, the appropriate tables will be automatically applied to get you to the most specific record for that classification number.
The Hierarchy Browser steps you through the classification data one level at a time. This differs from the Standard and Enhanced browsers as they display all of the levels of a hierarchy until a table is reached. The Hierarchy browser automatically applies tables as you navigate down. Like the Enhanced browser, when you type a number into the Find... prompt at the top of the screen, the system will apply as many tables as necessary to get to the most specific record. The Hierarchy browser keeps track of your current level and limits the display to that many levels of classification data. By clicking on the links that say Hide subtopics, Show subtopics or Apply table, you change the maximum depth the browser will go when returning a page.
Classification data is displayed a page at a time. You can change the default number of records returned with each ClassWeb request on your Account Settings page (requires administrative password). You can also set the number or records for your current session by starting the classification browser using the Bookmarks link found at the bottom of the main menu.
The classification browser screen is split into four sections. They are:
This screenshot shows all of the elements of a classification display. The hierarchy box contains the full hierarchy of the currently selected classification record. The current selection is highlighted in the classification display area with light blue highlighting. You can change which record is current by clicking on that record with your mouse. When using the Enhanced and Hierarchy browsers, each element in the hierarchy box except for the last is a link that will take you to a parent level in the hierarchy. For example, clicking on Industries. Land use. Labor will take you to HD28-9999.
Note: When using the Enhanced and Hierarchy browsers, tables are applied automatically in the display. In the current example, class numbers HD9000.1 and (HD9000.2) were calculated by applying Table H18. However, when typing HD9000 into the Find... box (see above), these calculated numbers did not appear in the drop-down list. Instead, the class numbers start with HD9000.9.A-Z. This is because the drop-down box does not apply tables and calculate class numbers — it just shows what is actually in the database.
When using the Hierarchy Browser, the last element of the hierarchy will often
also be a link. These additional links allow you to move deeper into the classification hierarchy.
If a term has not been turned into a link, it means that there are no further sub-topics under that one.
For example, in the Hierarchy Browser, HD9000-9999 displays the following hierarchy:
Clicking on Industries. Land use. Labor will take you up one level in the hierarchy and Special industries and trades will take you down a level.
This section of the screen displays one page of classification data at a time, indented according to their level in the classification hierarchy. The data may also contain tracings, references and table links. In the following screenshot, HG6046-6051, UC700-705, HD6941-6948 and HD9000.1 are all references to other areas of classification:
This example also shows how the Enhaned Browser will apply tables automatically.
In this case, the records after HD9000-9019 are from Table H18. If you click on the link
Food supply. Produce trade, the data from Table H18 will be hidden, like this:
When applying tables to classification numbers, there are cases when the entire table is not applicable and some of the table information is overridden. The overriding data comes from the area of classification which is applying the table. Whenever this happens, the table references will include the word modified. For example, in the previous screenshot, the record at HD9000-9019 contains the notice TABLE H18 modified.
In this case, all of the lines from the caption Inspection (HD9000.9.A-.Z) onwards
happen to be schedule records that override the records in Table H18 when that table is applied.
If you click on Food supply. Produce trade, Table H18 is applied and the results are merged with
the overriding schedules records, as follows:
When Table H18 is applied to this area of the classification, calculated classification numbers are generated for the table records and those records would normally be integrated into the display. However, if any of the calcualted classification numbers already exist in schedule records, they will not be displayed (they are overridden). When this happens, the overriding schedule records are displayed in yellow to indicate that these are modifications to the underlying table.
In the current example, the captions from Inspection to By region or state, A-Z are schedule
records (yellow highlighting) and the lines from By region or country onwards are from Table H18.
If you are ever uncertain about where classification records originate, use the Standard Browser, as shown here
Classification Record Links
Every classification record and tracing in the classification browser is followed by a little white button ( ) that displays a drop-down menu when clicked. In this example from the Enhanced Browser for classification number HD9000-9019, before clicking the button, the screen looks like this:
And after clicking the button:
The links may include:
|Dewey correlation||ClassWeb includes bibliographic correlations between LC classification numbers and Dewey classification numbers. This link will display the Dewey classification numbers that are most often used with this LC classification number. Note: This option can be removed from from the drop-down menu by changing your account settings. Click on the Options tab and uncheck the box Display links for Dewey correlations.|
|Edit this record||Only displayed for administrative users who have permission to edit this record.|
|LC subject correlation||Displays LC subject headings that are most often used with this classification number.|
|LCSH 053 search||Displays LC subject headings that contain this classification number in an 053 field in the subject record.|
|MARC record||Displays this classification record with its MARC tags.|
|Notes||Create or edit the local notes associated with this classification number.|
|OPAC(s)||Displays one or more OPAC links for this classification number. Note: Customize your list of OPAC links in your account settings.|
For accounts that are configured to submit classification proposal requests, the drop-down menu may include the following items:
|Modify or delete this proposal||Displayed on any proposals that have been submitted by your account prior to being assigned to a weekly meeting to allow you to modify or delete your proposal.|
|Propose cancelling this number||Create a proposal to cancel this classification number.|
|Propose a change to this record||Create a proposal to modify this classification record.|
|Propose a new class number here||Create a proposal for a new classification number using the current record as a starting point.|
|Propose a new reference here||Create a proposal for a new tracing or reference at this place in classification.|
Secondary Table Links
There are places in the classification data where a secondary table is applied after applying a primary table. In the Enhanced and Hierarchy browsers, these situations are handled automatically, as in this example at HF3221-4040.7:
One of six secondary tables is applied, depending which record in Table H7 is choosen at the next
level. Clicking on Other regions or countries will display this:
Moving your mouse over individual country names will display a pop-up help message that indicates which secondary table will be applied in that instance. Canada will apply HF3221/1 for a 10 number country. Haiti will apply HF3221/2 for a 5 number country.
On the other hand, when you use the Standard Browser, tables are not applied automatically and
classification number HF3221-4040.7 will look like this:
In the Standard Browser, you click on TABLE H7 modified to apply the table. The result is:
All of the captions that include a blue plus sign have secondary table links. In this case the secondary table is based
on the "number of countries". Clicking on the plus sign for Mexico will display Table HF3221/1:
Locating a Classification Number
LC classification data comes from two sources: schedule and table records. Unless you use the Standard browser or else run into one of those rare cases where the automatic calculation feature cannot apply a table for you, you will not be working directly with table records. If you do need to work with table records, you must click on the Tables button at the top of the screen before inputting your table and/or class numbers.
When browsing for a LC classification number, the data that is returned will depend on which class browser you are using. For the Standard browser, you will be taken to the closest schedules record to the number (or range) you entered. The Enhanced and Hierarchy browsers will attempt to apply primary and secondary tables and return the nearest calculated number to your search value.
When browsing for schedules records (either real or calculated), you input either a single classification number or a span (by separating the two numbers with a hyphen). Here are examples of single numbers:
Please note that you can use either upper or lower case characters when looking for classification numbers (i.e. "HD9000.9.A1" and "hd9000.9.a1" are equivalent).
Here are ways of inputting classification spans:
When inputting a span, you can use the shorthand notation of dropping the leading text characters in the second number (i.e. "HD9000-9999" and "KFN1-599"). Also, please avoid using any spaces in a classification number unless they are actually part of the number. Spaces affect the sorting sequence and may send you to the wrong place.
When browsing tables records, you must always include a table number in your request. If the table can be found, you will be restricted to that table while you are paging forwards and backwards. To work withn a diferent table, type in a different number.
Here are examples of table numbers without a class number or span (they will return the first page of the table):
Note that you can use either upper or lower case characters when inputting a table number (both "KFA-KFZ" and "kfa-kfz" are equivalent).
If you want to get to a particular place in a table, you can add a class number or span to the table number (separated by a space). For example:
How Classification Numbers are Sorted
Classification numbers are either a single number (like "HD9000") or a span (a range of numbers like "HD9000-HD9999"). The first number is sorted in ascending order but the second number is sorted in descending order (broader spans file before narrower ones and all spans file before individual class numbers).
Here is an example of sorted classification numbers:
A record that has a single classification number ("KFN1") as opposed to a span ("KFN1-599") will always sort after any others with the same first number.
Locating Class Numbers in the Standard Browser
When you input a single classification number (as opposed to a span of numbers separated by a hyphen) into the Standard browser, ClassWeb will return the broadest span that starts with that number (for example, "HF1" will return a page that starts with "HF1-6182"). If this is not what you want, you can add a hyphen to the end of a single classification number to indicate that you would prefer an individual class number. For example, to get to "HF1" instead of "HF1-6182", you would input:
Locating Class Numbers in the Enhanced
and Hierarchy Browsers
The Enhanced and Hierarchy browsers take the opposite approach to locating classification numbers. Using the number you input, they will apply primary and secondary tables to return the most specific classification record to your search value (for example, "HF1" will return a page starting with record "HF1" instead of "HF1-6182"). If you are inputting a single number (as opposed to a span) and you want to find the span that is associated with that number, you must add a hyphen to the end of your number to indicate your preference for a span. For example, to find "HF1-6182" (or the first span that starts with "HF1"), you would input: