While the Classic Catalog may be searched by keyword, sometimes searching within subject headings can be a great way to discover relevant titles. For instance, using the Classic Catalog dropdown menu to select Subject Heading and then searching for veterans will result in a list of titles under the broad subject heading term Veterans, as well as narrower terms (such as disabled veterans), related subject headings (such as retired military personnel), and subject heading search suggestions (such as Search Also Under: subdivision Veterans under individual wars, e.g. World War, 1939-1945--Veterans).
Screenshots below illustrate this type of subject heading search:
