The Editor is a tool used for adding, changing and deleting items in files. It is a line-oriented editor, and provides an assortment of commands that move the line pointer to specific attributes (lines) in the item being edited. The . (period) is the prompt when working in the Editor.
Since everything in D3 is an item in a file, the Editor can be used on any item in any file, unless otherwise prevented by retrieval or update lock codes. Each attribute in an item being edited is treated as a separate line. The numbers to the left of the attribute indicate the line or attribute number.