Legal indexers are familiar with legal concepts and classification and are able to translate the classification into an accessible index. Legal indexers are especially involved in the consolidation and updating of existing indexes, and also prepare tables of legislation and cases. Many periodical and newspaper indexes are based on a controlled vocabulary to ensure consistent use of terms from year to year. Periodical and newspaper indexers help ensure that an overview of the issues discussed throughout the life of the index are easily accessible. Newspaper and periodical indexes can be annual or cumulative.
Pictorial indexers are skilled in identifying and describing images in visual collections.
One growing area needing indexing is the information on the Internet. Despite the proliferation of automated search engines, there are a number of ways in which human indexers are needed to enhance access to information on the World Wide Web. Website indexes can be similar in style to back of book indexes or can be designed as hierarchical pages, which both link directly to the information required. They complement other navigational tools such as site maps and search engines. Metadata indexers improve the precision of access to Web documents through search engines by the use of standard elements similar to those used in database indexes and library catalogues.