100

Subclass marker (AcDb2dPolyline or AcDb3dPolyline)

10

DXF: always 0
APP: a "dummy" point; the X and Y values are always 0, and the Z value is the polyline's elevation (in OCS when 2D, WCS when 3D)

20

DXF: always 0

30

DXF: polyline's elevation (in OCS when 2D, WCS when 3D)

39

Thickness (optional; default = 0)

70

Polyline flag (bit-coded); default is 0:
1 = This is a closed polyline (or a polygon mesh closed in the M direction).
2 = Curve-fit vertices have been added.
4 = Spline-fit vertices have been added.
8 = This is a 3D polyline.
16 = This is a 3D polygon mesh.
32 = The polygon mesh is closed in the N direction.
64 = The polyline is a polyface mesh.
128 = The linetype pattern is generated continuously around the vertices of this polyline.

40

Default starting width (optional; default = 0)

41

Default ending width (optional; default = 0)

71

Polygon mesh M vertex count (optional; default = 0)

72

Polygon mesh N vertex count (optional; default = 0)

73

Smooth surface M density (optional; default = 0)

74

Smooth surface N density (optional; default = 0)

75

Curves and smooth surface type (optional; default = 0); integer codes, not bit-coded:
0 = No smooth surface fitted
5 = Quadratic B-spline surface
6 = Cubic B-spline surface
8 = Bezier surface

210

Extrusion direction. (optional; default = 0, 0, 1).
DXF: X value; APP: 3D vector

220, 230

DXF: Y and Z values of extrusion direction