Folio

The running number of the pages of a work. When there is no running title, the folios are placed in the middle of the head-line, in Arabic figures, sometimes enclosed in bracketsCrotchets, sometimes in parentheses, but more frequently now without either; when there is a running title, the folios are placed at the outside corners of the pages. The prefatory matter has the folios generally set in Roman lower case numerals, and sometimes the folios of an appendix are done in a similar manner.

A sheet of paper folded in two leaves, is also termed folio; as folio post, folio demy, &c.; but when the size of a book is spoken of, it is styled a post folio, demy folio, &c.