In manuscripts and early printed books, a catchword is placed at the bottom of a leaf (or sometimes at the bottom of the last leaf of a gathering) to aid the book binder in the correct ordering of the leaves and gatherings before sewing them together. The word appears after the end of the text block and it reproduces the first word (or syllable) in the text on the following page. Not to be confused with signatures, marginalia or printer's marks, all of which may also appear in the lower margin of a page.