Editing Codex (section)

===Pages===
Watermarks may provide, although often approximate, dates for when the copying occurred. The layout (size of the margin and the number of lines) is determined. There may be textual articulations, [[Page header|running heads]], openings, [[Chapter (books)|chapters]], and [[paragraph]]s. Space was reserved for illustrations and decorated guide letters. The apparatus of books for scholars became more elaborate during the 13th and 14th centuries when chapter, verse, [[page numbering]], marginalia finding guides, [[Index (publishing)|indexes]], [[Glossary|glossaries]], and [[Table of contents|tables of contents]] were developed.<ref name=":0" />