Lines are secondary chart objects. Lines connect symbols, and their existence depends on the existence of the symbols they connect. When symbols are moved or removed from a chart, any lines that connect to those symbols are modified or deleted accordingly. Lines have the following properties:
| Source | The identification of the symbol from which the line begins. |
| Exit Point | The side (top, bottom, left, right) and attachment point of the source symbol to which the line connects. |
| Destination | The identification of the symbol into which the line terminates. |
| Entry Point | The side and attachment point of the destination symbol to which the line connects. |
| Line Style | The pen style (solid, dash, dot) and thickness of the line. Also the type of route (auto, direct, curve) of the line, the size and number of arrowheads, and the text and location of a label for the line. |
| Color | The color of the line and label text. |
Lines that are added to a chart take on the current default properties for lines.