Classification Web is the Library of Congress's electronic version of the classification and subject headings. It is also sometimes referred to as Classweb.

Classification Web is only available by subscription, the price of which is related to the number of simultaneous users. This does tend to make it less accessible to small libraries, and unfortunately there is no educational rate. Nevertheless, for libraries where the budget can accommodate it, it offers a quick and easy way to use LCSH with all the advantages that a digital format affords. As the system is updated daily, it also provides the most current version.

The composition of Classification Web

Classification Web gives you access to both the Library of Congress Classification and the Library of Congress Subject Headings. We won't consider the classification specifically, but there are several ways in which the two are linked together that will be dealt with in this chapter.

As far as LCSH is concerned, the online tool consists of several distinct databases. The equivalent of the printed LCSH (the red books) is held in the main database, and this is what you will normally search or browse. Headings for particular forms and genres can be searched as a separate collection, although form and genre as subject are represented in the main list as well (the distinctions here are treated in more detail below). There is also a separate database of the free-floating subdivisions, which can be searched independently, or in combination using the advanced search. You can also look for name headings, which are derived from the Library of Congress name authorities. That is a useful device for establishing the correct form of personal and corporate names without having to search the name authorities as a separate exercise.

The classification data for the Library of Congress classification also forms part of the system, and various elements of LCSH link to that data, and to Library of Congress catalogue data. We will see below how this all works together.

Layout and format

Although the content of Classification Web's LCSH is to all intents and purposes the same as the printed version, it looks rather different on the screen. There are also some differences in the way structured headings are presented.