The subjects or topics covered in a publication, usually subdivided into chapters, sections, departments, or books, and referenced by page; also called "table of contents", and abbreviated "TOC". Also, the material or substance presented by topical categories. The contents page in a book is always recto; but the contents page of a periodical is often verso, with the opposite recto page usually being prime advertising display space. The contents, being a service page in a periodical, normally includes: heading, date, volume number, logo, subheads, titles, bylines, page number (or other form of navigation), deck/bite/abstract/teaser, images, cover credit, website address, and website contents. The contents for periodicals has expanded to two or three pages so feature and department titles could include decks or abstracts as teasers, supplemental images for the material, and a website contents within the print contents. If the corrigenda does not appear on the editorial page or with the masthead, it may be placed on the contents page. See pagination, editorial well, feature, sidebar, advance, front matter; compare ladder, masthead, colophon, concordance.