Designing multi-level indexes

Indexes often include more than one level of keywords. Multiple levels enable you to logically arrange keywords based on their relationships with other keywords, as shown here:

The top-level keywords (parent keywords) are more general and the subkeywords (subordinate keywords) are more specific. For example, the keyword "Caribbean" is a general classification. The subkeyword "Hotels" divides this keyword into a specific subclass. Similarly, both "Sandy Lane" and "Ocean Club" are subkeywords of "Hotels."

Guidelines for multi-level indexing