| StartTag | S | Tag to annotate the start point of the alignment segment. | Text |
| EndTag | E | Tag to annotate the end point of the alignment segment. | Text |
| StartDistAlong | S | Distance along the horizontal alignment as measured along the corresponding | Number |
| HorizontalLength | L | Length measured as distance along the horizontal alignment of the segment. | Number |
| StartHeight | H | Elevation in Z of the start point relative to the IfcAlignment coordinate system. | Number |
| StartGradient | S | Start gradient of the segment. | Number |
| EndGradient | E | End gradient of the segment. | Number |
| RadiusOfCurvature | R | RadiusOfCurvature | Number |
| PredefinedType | P | Predefined type of the horizontal alignmnent segment. | Text |