The following group codes apply to xline entities.
Xline group codes
Group code
Description
100
Subclass marker (AcDbXline)
10
First point (in WCS)
DXF: X value; APP: 3D point
20, 30
DXF: Y and Z values of first point (in WCS)
11
Unit direction vector (in WCS)
DXF: X value; APP: 3D vector
21, 31
DXF: Y and Z values of unit direction vector (in WCS)