A supplement is a publication that has a role secondary to that of another preceding or concurrent publication. A follow-on publication complements its predecessor, either by bringing it up to date (e.g. the Index Catalogue), or by otherwise enhancing the predecessor's coverage of a particular topic or subject matter, as in the Tosefta. Supplements are particularly used in gaming hobbies. Some supplements are spin-offs from a newspaper. They are sold separately and typically cover a specific topic, such as the Times Literary Supplement and the Times Educational Supplement